Adaptive Armor

Powered Armor is a very fearsome tool and weapon, even capable of making the wielder a Lightning Bruiser with the Alpha Strike capability to One-Hit Kill most enemies. However, despite its potential for great versatility with in built Swiss Army Weapons, it will always look and do the same things regardless of the driver.

This isn't the case with Adaptive Armor. Whether it's a benevolent symbiotic entity, a mystical suit of armor, or armor so advanced it seems magical, this suit of armor will adapt itself to any wearer in order to enhance their greatest strengths and potentially minimize their weaknesses, even going so far as to give the driver a form of Personality Powers based on their desires or talents.

The adaptability doesn't stop there, either. The armor likely has a greater or lesser chance of giving the wearer a Swiss Army Arsenal, resistance via exposure to enemy attacks or environmental hazards, and a Healing Factor courtesy of Nanomachines, Power Crystals or biological symbiont. Sometimes these powers act like a Green Lantern Ring that become "set" as the wearer needs them, until the armor stops being able to "adapt". The armor itself is likely to have a mind of its own, if not at least a personality that makes its moods known to the wearer. In these cases, the mind can usually activate the armor's Heroic Safe Mode to protect the user in case of accident, unconsciousness or Mind Control. Mind the Tranquil Fury with no regard to friend and foe.

Also, in a pinch it can change appearance based on the wearer's alignment. If there's more than one suit of Adaptive Armor or the wearer ever loses the armor or has it forcibly separated, anyone else who wears it will have a similar but distinct look, or it will be incensed that it's been stolen and work against its new "master."

Anime and Manga

 * The Guyver units are this. They all share similar capabilities, but each one looks vastly different. Humans, who were created by Precursors as Living Weapons, gain exponentially more power from the suit than the aliens themselves, as well as inexplicable immunity to their Mind Control abilities. It is implied that a Zoalord who equipped a Guyver unit would have power approaching that of a god.
 * Also consider that said Precursors, who were probably not a single species, created them primarily as space suits: i.e. they were developed to supply the physiological requirements of pretty much any nitrogen/oxygen breather without drawing on anything from the immediate environment.
 * To a greater extent, the Guyver Gigantic, which changes appearance to match the Guyver wearing it.
 * The Berserk Armor that Guts wears is this trope. Besides the fact that the helmet shape changes form according to the wearer's inner beast (in Guts's case, the dog-like beast), it increases the wearer's endurance and power, but at the cost of allowing the wearer to surpass their physical limit by making their subconscious unaware of physical injuries (though while wearing the armor, massive wounds can be temporarily healed - but this is done by the armor piercing splinters through the skin). Oh, and it also causes temporary insanity by making the wearer go berserk, and is insinuated that long term use will cause mental deterioration. It is a cursed piece of armor, after all.

Comic Books

 * The new Blue Beetle has armor that basically functions as a high tech/quasi mystical Green Lantern Ring.
 * The Beta Suit in Echo cushions against g-forces, can emit deadly electrical attacks, cures diseases and can even re-write the DNA of its wearer. Unfortunately, as wonderful as it is, Julie just can not get the darn thing off.
 * The alien symbiotes (Venom, Carnage, etc.) of Spider-Man fame are examples of this.
 * In Weapon Zero, everybody super is so because of an adaptive armor. And the armors show complete disrespect for the law of conservation of mass (at a whim shrinking away to nothing or growing very thick).
 * The Witchblade is definitely one of these.
 * Wetworks is another comic where the titular team's most distinctive trait is the liquid "gold" armor covering their bodies. While initially just making the wearers effectively invulnerable, "the gold" later turns out to have other powers as well.
 * Commanda, an obscure villainess from Untold Tales of Spider Man, wears a suit of armor that can generate a force field, fire electric shocks, and change its shape and appearance at her will.
 * X-O, from the comic of the same name produced by Valiant. The original version is an alien-created series of power armor with the most powerful being the Man-O-War class of armor. So powerful almost none of the aliens even have the mental and physical abilities to use one and in the hands of a Visigoth slave responding to his powerful will the armor can adapt and grow to deal with virtually any situation, sustain its wearer almost indefinitely and heal nearly any injury (having his stomach slashed open simply had him trapped in the armor for 10 years while it repaired him). It was even capable of regenerating someone else's arm when ordered to do so (although again this took time).

Literature

 * The boringly but appropriately named Suits in Alastair Reynolds Revelation Space books are this, effectively turning their wearers into Flying Bricks and providing a pretty devastating range of weapons via a Hyperspace Arsenal. They're potentially smart, but not sentient or intelligent. Capable of operating independently as an Attack Drone. Used quite casually by the super-high-tech Ultras, but considered an exceptionally rare and valuable weapon of Game Breaker status by the embattled citizens of Sky's Edge.
 * The Culture also has suits, named in its usually literal way Suits, though as with most Culture technology they're controlled by an AI (usually of the lower end of the sentience scale) rather than being passive tools. Flying Brick capabilities come as standard, but offensive weaponry beyond the Effector would not be generally issued. Being sentient, they can also operate quite independently of a wearer if needs be and are not practically stealable.
 * The Droods in Secret Histories are best known for their "strange matter" armor, given to them by a friendly Eldritch Abomination named Ethel. The armor is effectively indestructible (although it has notably never been tested against an actual atomic bomb), has a Glamour field that makes its owner Invisible to Normals if they want to be, and is capable of changing its style and shape based on the owner's will. It is implied that its only real limitation is its owner's imagination, and later books have the armor using new tricks like gliding, hacking computers, and growing machine guns that fire powerful strange matter bullets.

Multiple Media

 * Coincidentally (as it came before the trope was defined ), Bionicle had the Toa Nuva acquire gear called Adaptive Armor just before they went to Karda Nui. True to the trope, said armor can adapt to terrain and enemies; it gave them flight capabilities (propellors, wings, jetpacks) for Karda Nui's sky-high setting and light energy weapons for use against the shadowy Makuta.

Tabletop RPG

 * In Champions this would be done with a Variable Power Pool using the Focus (power suit) and No Conscious Control limitations.
 * In Mutants and Masterminds' core setting Freedom City, this trope is filled by the Star Knight Corps, combined Expys of the Green Lantern Corps and ROM Spaceknight

Video Games

 * The Allies in Command & Conquer: Red Alert 3 field the Multigunner IFV, an adaptive jeep that would power up any infantry put inside (including the other factions'). There was also a base defense version. Hilariously enough, a Multigunner Turret seen through the fog of war would appear to have all its possible addons, including several guns, a missile rack, a lightning gun, a freeze ray, a plasma beam, an energy bow, a ninja star launcher, and some kind of automatic repair arm.
 * Don't forget this trend started with the earlier, bog-standard IFV of Red Alert 2. While lacking anything quite as awesome-sauce as a freeze ray, placing President Dugan in one certainly caused a fantastic light show...
 * Kid Icarus: Uprising downplays this during the final chapter, but it's still there.

Western Animation

 * Crash Nebula, protagonist of the Show Within a Show of the same name from The Fairly OddParents, has this kind of armor.
 * In The Avengers: Earth's Mightiest Heroes, Captain Mar-Vell's armor-suit can morph into various weapons.
 * In ThunderCats (2011), series Sorcerous Overlord Lich Mumm-Ra uses Power Crystals as Amplifier Artifacts to transform a gauntlet into a custom set of skeletal armor. When young Catfolk hero Leo acquires a duplicate of the gauntlet and steals one of the crystals, his gauntlet transforms into golden lion armor. When his successor Lion-O acquires a crystal, it turns his claw gauntlet into full armor covering his entire left arm.

Web Original

 * From the Global Guardians PBEM Universe, Rainbow Knight's "Powered Armor" is actually a piece of alien biotechnology that molded itself onto his body. Beyond some standard capabilities (like superhuman strength, invulnerability, and flight), the armor's capabilities change depending on the wearer's needs.