What comic book character has the biggest gap between their best stories and their worst stories?

I don't mean a character who is consistently great or consistently bad. I'm talking about characters where, at their absolute best, they're genuinely incredible, but at their worst, the writing makes you wonder how the same character got both versions.

My pick might be Batman. At his best, you get stuff like The Long Halloween, Year One, The Killing Joke, The Court of Owls, etc. But because he's been around for so long and has been written by so many different people, there are also some runs where the character gets pushed so far into "Batman always has a contingency for literally everything" territory that he stops feeling like a compelling character and starts feeling like a plot device.

Who would you guys pick?