Have to agree with the blighttown comments, my frame drop there is unnoticeable 90% of the time, and without that it was an annoyance but nowhere near as bad as the Tomb of the Giants. Pinwheel servants on the way in, giant skeletons when you get there and in the final room, enemies that are pretty much a carbon copy of the boss you just fought and tiny skeletons that inflict you with toxic (so damn annoying) swarming you.
Also, OOT water temple, but I think that's a case of it becoming such a big thing and me playing the easier 3ds version. I can see how at the time it was a ***** to do.
And others... pretty much the whole of Skyrim. That feels horrible to say considering how much I love that series, but I just don't like the layout and style of skyrim. Cyrodiil may be generic fantasy 101 but it's a damn sight more fun and interesting in my eyes.