Top 3 best:
Cap - Loved how is arc ended, got the ending the character deserved.
Iron Man - Again, done total justice that the starter of all this deserved. RDJ went the extra mile here.
Hawkeye - Finally getting some time to shine and a decent arc with it, interactions with BW were great.
Bottom 3:
Hulk - Not sure what they were trying to do with this character, sidelined for the most part.
Thor - Overplayed the "fat" Thor jokes, but he was probably top dog in IW so evens out a bit.
War Machine - Never really got show off his action muscles as much as I wanted.
MVP - Probably IM just about takes it, he was the heart beat of the film.
LVP - Captain Marvel, forced into the film when it would have been perfectly fine without her.
Most improved - Ant-Man finally me like him after his rather dull solo movies, Rudd was charming and witty throughout. Added a lot to the whole thing.