any boss that can cap (yes, there are some that can't cap) is insta-<3
bosses i hate? the ones that have access to hitscan weapons(bill is an exception due to being surprisingly well balanced for a boss with multiple lives and an SMG). if there was a way we could make it so the shots they fire were like pomson shots at least, i'd like them all, but the one i hate the most is Doctor Who. he takes this to ubsurd levels of OPness by being able to pick up ammo, something that i've been abusing the fuck out of to get a point across whenever i'm him.
boss i'm best at? idk really.