I make it a point to do the following:

1. Recognize that a fictional character is just that.
2. Place the blame for unlikable portrayals where it belongs: writers & editors.
3. Be open to better portrayals without holding a grudge over worse portrayals.

A good example of this is Victor Creed. The evil, stupid, mindless killer version bores me. The Age of Apocalypse version or the inverted version were both interesting

On the other hand, I've yet to enjoy any story with the Sentry. The first reason is that the evil or mentally ill Superman character concept has been done to death, and it has been done far better elsewhere than in any Sentry appearance I've read. The second is that I'm not a fan of the whole trope "the world magically forgot this character" trope to be uninteresting. Same thing with Triumph over at DC.