Traps I hated:
- Ayleid red crystals. They turned a nice dungeon dive into a horrible nightmare that wasn't fun at all!
- Darts from the walls. There was no trigger! And you never knew when they'd get off. God, I hated them.
Seriously, I think there should always be a way to disable a trap somehow, or to avoid it. Or at
least to see the trigger that's starting it. I mean, many times there really was no other option than getting hit a couple of times by those red crystals, often while also fighting some bad guys. That's not good design, in my opinion, because certain types of characters don't stand a chance in these situations - namely the ones that would usually be cunning enough to find a way to disable those traps before they can harm them.
That said, all other traps were pretty cool. But while those huge, impressive and nasty traps in the Ayleid ruins were awesome if you wanted that certain Indiana Jones feeling, I generally prefered the ones that actually made sense. Hopefully for Skyrim, they'll find a way to combine these two extremes. For example if some dungeons have secret sideways where all the mechanics for the traps are, which you can then destroy (or repair)... or if there is some lore about it that makes them seem plausible. Or if most of them actually only work one time, and after that they have to be readjusted. (The swinging blades and the spike-grids-on-a-rail in the Ayleid ruins come to mind - to what kind of perpetuum mobile were they connected?!)
Speaking of Indiana Jones, anyone remember the IEHOVAH maze in The Last Crusader? I'd like to see something exactly like that. The ones in Oblivion where you simply triggered darts if you stepped on the wrong plates were boring.
Hm, actually I also want that other trap from before. It was nice because once it appeared, you could see the mechanism that runs it.