8. Captain America's Exoskeleton
During the 90's a lot of attempts were made to bring older characters up to date with what was cool at the time. In practice, that meant that every hero was given either 500 pouches, a gun the size of a car or a giant suit of power armour.
We collectively made some bad choices about what was cool in that decade.
As you can see, Cap got a powersuit. It was as part of a story in which the super-soldier serum in Steve's body began to fail and so Tony Stark built him an armoured exoskeleton. Unfortunately, Tony Stark is also apparently a petty jerk who wants to be the only one to look good in armour and so he built the goofiest looking suit imaginable.
The whole thing just looks so unwieldy, it's a wonder that Steve could even fit through a door in that thing, never mind fight the Red Skull. And what's the point of having a single bit of armour over his nose? Is he afraid that Baron Zemo will trick him with a "got your nose" prank?
The exoskeleton is a prime example of a lot of this list, it's a completely unnecessary change that adds absolutely nothing to the character. Captain America is supposed to fight for justice using his own battle-hardened skills, not stomp around like a reject Transformer.