If there's one boss that got me close to rage quitting, it's the Spider Guardian from Metroid Prime 2. I hate that boss so much, and it's not that it's that hard theoretically. You just bomb it until it glows green and then go into a bomb slot and activate it. But there's a few things in the way. First, there's a time limit. Second, the guardian delivers a lot of damage if you hit it. Third, the environment can be difficult to navigate.
I can't tell you how many times I screwed up because of something in the environment, for instance trying to use a half pipe only to go onto the wrong platform and having to start over, or trying to get to a bomb slot that's located on a hill and having to balance on the hill and make a bomb before you roll all the way down.
The time limit makes things even tougher. It's worse at the end when you have to bomb 3 slots in the same turn. This means there's little room to diddle dally and more room for error when you try to get to the upper 2 bomb slots, both of which are on a hill, a slant.
Adding salt to the wound, the nearest save room is several rooms away. While looking a map it doesn't seem that bad, but the map doesn't show you the obstacles you have to go through, and doesn't include the fact that you must face off against a new dark creature (which has a buddy) and you have to talk to a luminoth and go through that cut scene every time you lose against the Spider Guardian.
So yeah, I really hate the Spider Guardian.