X-Men Legends

Xtreme alternate costumes:
Press Up(2), Right, Left, Down(2), Start at the main menu. During game play, go to an Xtraction save location and use the button next to "Skin".
degrpmand HBK.

Alternate costumes:
Successfully complete the game to unlock the classic costumes (Bobby Drake/original Iceman, 1990's Colossus/without metal, original Beast, 1980's Cyclops, original Jean Grey/Phoenix, original Nightcrawler, street clothes Magma, 1990's Wolverine/Weapon X).

Play as Storm:
Successfully complete level 1.

Play as Emma Frost:
Locate Emma Frost in X Mansion after the Nuclear Facility level.

Play as Colossus:
Successfully complete the Nuclear Facility level.

Play as Beast:
Successfully complete level 1.

Play as Cyclops:
Defeat Mystique in the New York City Riot level.

Play as Gambit:
Successfully complete level 3.

Play as Ice Man:
Successfully complete level 1.

Play as Jean Grey:
Successfully complete level 1.

Play as Jubilee:
Successfully complete level 2.

Play as Magma:
Successfully complete Magma's second training round.

Play as Nightcrawler:
Successfully complete level 2.

Play as Professor X:
Enter the Astral Plane for the first time.

Play as Psylocke:
Successfully complete the New York City Riot level.

Play as Rogue:
Successfully complete level 1.

Artwork:
Collect all 19 Sketchbooks to unlock the artwork in Colossus' room.

Stat increase:
Collect the hidden Comic Books to increase your characters' stats.

Bonus Danger Room tasks:
Collect the hidden Danger Room Discs to unlock more tasks in the Danger Room.

Hint: Defeating Marrow:
Use the following trick to defeat Marrow after GRSO soldiers have attacked the tunnels. At first is seems very difficult, but it is best to have someone such as Storm on your team who can fight at long range. After killing Marrow and all of her henchmen, two Marrows will appear. One will have a green shield and will appear under one of the torches. Instantly do Cyclone Fury with Storm or another Xtreme long range power. This will kill her. You will still have to kill the other Marrow. Then, try to find the special Marrow after each kill of the regenerating Marrow. After you have killed the special Marrow three or four times, just defeat the other Marrow.
Jean-Paul Gleeson.

Hint: Defeating Mastermind:
To defeat Mastermind, first use Wolverine and slash away at his feet and jump when he steps. When the three Sentinel Controllers come out, fight them and dodge Mastermind's missiles by running in circles around the generators. When he gets his shield, turn on the three generators and wait until it goes away. From now on, use a long range fighter to finish him off. Remember to dodge the missiles.
J Earl.

Hint: Defeating Mystique:
Get to level 2 with Wolverine and get many healing potions. Attack her with R1 + X until she dies.
spino234.

Hint: Defeating Sentinels:
Choose Wolverine (at a high level) and run behind the Sentinel. Choose the Brutal Slash attack (R2 + X) and repeat it until the Sentinel falls.
james lahaie.

Have Colossus get Bands Of The Gladiator and Legend Smash. Two hits will drop them.
Dan Bush.

Hint: Extra health and energy:
When you receive a new course in the Danger Room, do not complete it. Instead, fail as much as possible. Every time you do the course, you will receive health packs, energy packs, armor, etc.
boyjlo.

The best way to get a extra utens is to fail the Danger Room courses. If you complete a course, the next time you send in your team they will not receive anything for their trouble. However, the first "final exam" as a freshman is a very easy one. Just do not destroy the generators. By doing this, your team can run around kicking butt for quite awhile and collect a lot of times. Note: Make sure all your teammates are set to auto-refill their health at 80% (this can be changed in the first field of the detail view for your characters). Also, watch for the inevitable cut off time (about a half hour in). At this point, the villains will no longer give anything up. Then, destroy the reactors and leave. Make sure to sell Forge anything you absolutely do not need; otherwise about halfway through your available time your inventory will be full and you can miss out on some good items.
torigirl.

Hint: Easy experience:
Make sure you find the "Focus 601" Danger Room disc. Once you have passed the exams (Qualifying 100, 200, 300, 400, and 500) and can access the "Legends" menu, select "Focus 601". In this mission, you must defeat five Master Acolytes, which will give you over 297,000 experience points each. Each time that you do this mission successfully, you are guaranteed at least 1,100,000 experience points.
Gremlin.

Go to qualifying exam 400 and keep failing it. Do not worry about Professor X; just keep killing Astral Fury about for 117,000 experience each time. Colossus can kill them in one hit.
Dan Bush.

To do this trick, first have Storm and Cyclops learn the Leadership ability. This works best if the skill is at the maximum. Once done, always have Cyclops and Storm in your party with two other members that you want to level up. Start fighting your enemies, except this time use your abilities more often. This ability will work once you execute a combo with either Storm or Cyclops' abilities. It should give you extra damage and experience points. To make this even more beneficial, try your best to execute a combo with both Storm and Cyclops' abilities. This should double the normal amount of bonus experience and damage. The Leadership ability's maximum capabilities is at 150% damage bonus, and 25% experience bonus; and if you managed to combo both Storm and Cyclops' abilities this should dish out a 250% damage bonus and 50% extra experience. This trick should be used in the Danger Room Focus 601 or Qualifying Exam 400. These are the areas that give most experience points with the most time for you to dish out your attacks.
Pierre Go.

Go into the Danger Room and choose Challenge: Legends. Take Cyclops, Storm, Jean, and anyone you want to level up. When you defeat the first three Bosses, switch to Jean and go to the middle area between the first two doors. Use Psychic Shout to rack up experience. However, do not finish the challenge. Let time run out and retry. You can reach level 40 and beyond very quickly by doing this. Note: Storm's Chain Lightning or Lightning Legend also works well.
Rayvn Lighthawk.

First, you must have the "Challenge - Legend" option available in the Danger Room. This trick will also be easier with the Mask Of Xorn (gives you unlimited mutant), but when you complete the challenge you will get it. First, have Cyclops (or anyone else with a range attack) on your team. Have him or her equip the Mask Of Xorn and place anyone else you need to level up on the team. At the beginning of the simulation, there are three generators (there are really four) and one further down to the end. Destroy the two on either side (left and right) and leave the one in the middle or at the bottom (do not destroy it). Then, run up dodging Marrow (if desired). Next, make a right and destroy the single generator. Then, run back down to the beginning where you left the middle generator running. Using Cyclops (or other ranged person) as your main character, start blasting anything that moves. Use your mutant power as much as desired, but stay near the beginning. Notice the objectives at the bottom right hand corner. When you are done destroying the forty enemies, notice that three out of four generators are destroyed and the timer is still going. This is your chance to get as many experience points as possible. When the timer reaches about ten seconds, blow up the last remaining generator. This is why you should stay near the beginning. This should result in at least ten million experience points.
jp_persad.

Hint: Easy kills:
This trick works best at the start of the game. Have Rogue in your party and level her up quite a bit. Now once you have skill points, use it on Southern Strike/Smash and increase the abilities level as far as possible while you are playing the game. Use it on your enemies and it should either kill or take out a large amount of HP. Combine with Leadership to deal more damage.
Pierre Go.

A fast way to kill enemies without any powers is to simply corner them. Get one of your characters to hit the enemy to the wall. Get the other characters to form a circle around the enemy. Once you have done that, keep pressing X, Circle, or combos in order to quickly kill them.
RobA.

Hint: Easy Sentinel destruction:
Equip an energy-based member with the Hammer of Nimrod (+125 to 150 damage to Mutant abilities vs. Sentinels). If you have upgraded Point Blank Shot and their main projectile attack, they should be able to stomp out Sentinels with one or two shots. This is especially effective with Jubilee, Magma, Iceman, and Gambit, as they fire multiple projectiles. When their power is maxed out to Legend and Point Blank Shot is also maxed out, they deal a minimum of 1837.5 points of damage with a melee-range attack. Sentinels are big. All seven should hit for at least 262 damage per projectile. This is the most efficient method, as Iceman is also useful for levels with fires, Gambit and Jubilee are useful for levels with targets to destroy, and Magma is useful for levels that need welding. Iceman and Magma can both make bridges. This allows you to prepare for multiple situations by simply swapping around the Hammer.
ironhandSoverign.

Hint: Throw Wolverine:
Any character with at least one point of Might can lift and throw Wolverine as a physical projectile. It is possible to toss him across gaps with this move, so you can switch to him in mid-air and clear the landing zone before another character makes a bridge or hits a lever. Be careful however; if you miss the other side, you may very well throw him to his doom.
ironhandSoverign.

Hint: Make other people fly:
Choose someone like Storm and tap Triangle(2) so that she flies. After she is in the air, have one of your nearby teammates press Square. She will pick him or her up and you both will be flying. To drop them off, go down towards the ground.
matta convouya.

Hint: Unlimited combo:
Start the combo by pressing Circle then X(2), Circle(2), then keep repeating X(2), Circle(2), X(2), Circle(2), etc. It is a lot easier if done slowly and you wait for the character to swing.
FATE215.

Hint: Icy swords:
Iceman's second level of Ice Armor, called Ice Equipment as well as the third level, Ice Forge, allows him to protect himself and power up his teammates at the same time. When the power is used, all members of the team gain an energy damage bonus to their physical attacks for as long as the power lasts.
ironhandSoverign.

Hint: Making bridges:
This can be done with Jean Gray, Magma, or Ice Man. For Jean Gray, hold R1 + X. For Magma, hold R1 + Circle. For Iceman, hold R1 + X.

Hint: Recommended team:
The strongest team in story mode consists of Cyclops, Iceman, Gambit and Wolverine. The idea is to pump up Wolverine as much as possible. Maxed out all the following boost skills: Cyclops - Command, Iceman - Ice Forge, Gambit - Kinetic Mastery, and Wolverine - Unstoppable Rage. Simply assign these skills to your help button (AI Skill), During battle press that button to pump Wolverine and activate Unstoppable Rage. Wolverine will move and attack very fast, dealing a large amount of damage that can kill almost all enemies without the help of others. For best results put some skills or max out Cyclop's "Leadership Skill". Equip Wolverine with Muscle Accelerator or Super Accelerator or whatever is available in your inventory that can enhance Wolverine's speed. You can also try The Hammer of Nimrod vs. Sentinels, The X-Cutioner Hood vs. Mutant, The Exodus Cloak vs. Humans, or Shadowcat's Touch vs. Robots.
NEAKHIZ.

Jean Grey, with an upgraded Psychic Shout, can clear rooms of anyone not mental resistant. Storm, with Lightning Bolt upgraded to Chain Lightning, can clear rooms of those without an energy resistance as her lightning leaps from enemy to enemy. Wolverine is the best at what he does, making short work of enemies that are not physical resistant on an upgraded Strike stat with the unlimited combo: also his Healing Factor allows him to wade into a melee relatively unconcerned. Nightcrawler is the final piece, because his Leap of Faith ability allows you to focus on taking enemies down. If any of your characters is about to die, Nightcrawler will save them from the fatal blow and teleport them out of the fray. Switch to that character, heal, and return to the action. This team will allow you to deal with a wide range of threats very quickly. In addition, Jean Grey can make bridges with Telekinetics, Storm can weld and destroy objects quickly, and if you in two player mode, Storm and Jean can both fly and both pick up a character, allowing you to ferry both non-fliers across a chasm or fire or any other barrier at the same time. Note: do not control Nightcrawler; Leap of Faith does not work unless he is CPU controlled. Leadership from Storm can also garner bonus experience.
ironhandSoverign.

Glitch: Unlimited Savage rampage:
You must have X-treme tokens to do this. Hold R2 and keep pressing Triangle. Note: This only uses one X-treme token.
kevbbach.