The only two things I really hate are the killmoves enemies use on you - when the game works out whether to use a killmove or not it doesn't take into account your armor - and when my allies/summons are blocking up a hallway an enemy boss is spamming chain lightning down
When I was doing the Thieves Guild quests, I ran into so many bugs that I wanted very much to chuck my game out the window and delete those saves. I obviously still have my game, but I couldn't bear playing that character anymore. What with the f'ed up quest just laying around like that and the NPCs screwed to hell.
Then, before I fixed this with a mod, the auto-aiming feature with archery killed my companion more times than I could count. Autoaim doesn't let you do the cool wood elf thing and shoot just over your companion's shoulder at your enemy. Instead, it locks on to the nearest body part (companion's shoulder) and hits that instead. Once you remove that tendency, it works much better and you can pull off awesome tricks like that.
Hmm. First one was Karliah wouldn't show up in the sanctum when you get shot by her arrow, so the cutscene never played. Then she wouldn't go into the Nightingale Hall without a lot of console help. Then she almost got stuck with Brynjolf when we were going after Mercer Frey. Then she wouldn't go to the Twilight Sepulcher and open the door for me. It was at that point that I gave up on even finishing the Thieves Guild.
Sure. It's worked well thus far. I've actually had to really work on my aim to get back to doing headshots again.
Oh, I've had quite a few of these. The only one that comes to mind at the moment was when I was running through the Thieves Guild on my Dunmer nightblade. It was the quest to hunt down Mercer Frey in that Dwemer ruin near the end of the questline. There was so much freaking lag after a certain point that it became almost unplayable, and it led to quite a few deaths to Falmer. I quit playing that character for a while because of it. I eventually managed to power through it a week later.
My very first character was almost lost 30 hrs in. I could only walk maybe five minutes before my game froze. So when it finally seemed to work after trying over and over, of course I saved...game froze again. So at that point I had two saves that were corrupt. At this point I am freaking out, considering just giving up on this game for a little. I decide to try to load one more autosave prior to the corrupt save and THANK GOD it worked!