Least favorite (By characters), there are so many I'll just do a few DC characters and two Marvel characters right now:
Batman: Frank Miller's batman, specifically the version from All-Star Batman and Robin. A rambling nutjob, and I'm talking about both this version of Batman and, at this point, Frank Miller.
Wonder Woman: I have multiple, so
--1) WW from JLA: Act of God. An obscure one, but really, really terrible, she basically loses her powers and becomes a fanatical follower of God (the Christian one, FYI although it could have been any and with the same writer would have been as bad, although since she's an Amazon who has actually met her gods it makes her weird Christian turn worse).
--2) Frank miller's Wonder Woman from All-Star Batman and Robin (She hates all men and acts like an asshole, but Superman can "tame" her
)
Superman: Overall its Zach Snyder's "Superman", but if it needs to be from the comics then its the New 52 Superman (the one from 2011m until he died).
Starfire: Continuing what is going to be a trend, the New 52 Starfire with her goldfish memory, emotionless sex with literally any living man who wanted it, and having no other real personality besides that until the backlash forced Lobdell to stop being a weird, pervy creep and try to give her some character.
"Shazam": The orphan with a heart of gold becomes a selfish ass who shakes down the very first woman he saves for money. he never really grows past that, and stays a selfish, whiny brat until they basically just phased him out. Since the Original Captain marvel is both my favorite DC hero and mostly tied as my favorite hero ever (with She-Hulk), this all pissed me off a lot.
Power Girl: The New 52 version from New 52 Earth 2 that was introduced as basically Mr. Terriffic's sex toy, and then just mostly spent all her World's Finest appearances partying, having random sex and sometimes trying to get back to Earth 2 with Huntress but having no real personality outside of sex crazed party girl. She had none of the personality or traits of the old PG, and since the original PG is my second favorite DC hero I really, really hated this version, even after they rewrote her from sex obsessed party girl into the woman who only existed to be Val Zod (second Earth 2 Superman)'s love interest and just made her bland in the Earth 2: Society book.
Bonus Marvel entries because I had to breing it up:
Hulk and She-Hulk: Old man Logan versions, where Mark "I'm Completely Out of My Mind" Millar made them into an incestuous couple who had produced cannibal redneck children. I don't even know if they show up in the book or if its just their kids, but its still easily the worst versions of both characters.
