I'm pretty much just parroting everyone here, but:
Time Limits, these are usually there just to make me scream incoherently, and even when I can succeed at the mission/event in question, I don't enjoy it because I spend the entire time worrying about how much time is left on the clock, even if I have a significant lead.
Quick Time Events, when poorly implemented. I can see a quick time event working well when it's an optional thing that the PLAYER can initiate, but popping these into cutscenes or making it a frequent, environment-initiated and required part of gameplay turns them into diabolical engines of frustration.
Completely Regenerating Health, because while having a layer of protection you can rely on when you're on your last legs is great, but cowering behind a corner for a few seconds to make it like you were never clumsy enough to get hit in the first place is terrible. It usually breaks the pace of the game, it breaks immersion (for me, although I can see an argument going the other way), and usually means that developers will compensate the reduced difficulty of health management by giving you hardly any health (which results in EVEN MORE FREQUENT hiding until the mortal wound fades away).
Singleplayer Weapon Limits, seriously. I'd rather developers let me deal with the presented situations with all the tools I've encountered up to that point, not just the ones they think I'll need to get to the next segment.
Checkpoints without Quicksave Options, although I understand the useful nature of the autosave, preventing me from saving progress between checkpoints is incredibly frustrating, especially over the more difficult segments. It also discourages me from trying new/risky things, which often results using the same tactics over and over, not necessarily because I enjoy them but because I feel like I'm being punished for trying anything else.
Idiot RTS Campaign AI, because it feels silly if my opponent never builds any more units than the buildings/army it starts with and just stands there until I move into sight.