Quick time events. Also:

Haha. That song is unfortunately  hiliarious.

Forced motion controls. It's nice that you have them but why not give the player the option when he's already using a controller with buttons.

Totally not looking at you, Flower.

Enemies that can instantly 1-Hit KO you.

It's super cheap in RPGs where you'll find an enemy that can kill you with that one attack rather than it being over leveled or having a strategic advantage :P can't tell you how often Ive had to redo whole areas just because of a cheap enemy that can wipe my party out with 1 move

those quick time button presses. UGH

1. Motion controls. They never work right, only make games worse 100% of the time. The true cancer from last gen.

2. Quick time events. If the best you can do is make "interactive" cut-scenes, you're doing it wrong.

3. Button mash, aka destroy your controller, events. Controller manufacturers love these, though.

Not really a mechanic, but missions which are too damn long!

1 hit kills.

Enemies that all attack you and ignore your squad mates in single player shooters.

Timed or rushed stages where one wrong step equals death.

Lacking adequate checkpoints, specifically before cheap death parts.

bosses that summon a bunch of minions up your ass constantly.

Bosses that keep coming back into multiple forms when you think the fight is over.

Unskippable cutscenes, especially during hard parts in which you will probably die.

Enemies and bosses that warp all over the damn place like crackheads.

In general anything that ruins the fun in a game. So many times I play games with cheap frustrating bullshit that no one could possibly enjoy and I have to wonder if none of the developers ever noticed how stupid these things are. Then I start to think maybe it is payback for all the whiners and trolls that attack them on twitter nowadays.

yup.. but I feel more a viewer in this game then in Heavy Rain.. don't actually feel that anything matters with my clicks on the buttons

1) Automatic camera angle in 3rd person 3D games, unless it's implemented almost perfectly. Even if impemented perfectly, I prefer to be able to choose a fixed camera angle, generally behind the shoulders.
2) Control input axes solidal with the screen instead of the playing character in 3D games.
3) Having to jump through series of moving platforms and the like, dodging series of crushing ceilings and walls, grinding gears, if not for a few limited sections.
4) Power-ups in racers.
5) Not being able to pause to command troops in RTS and real-time tactical games.
6) Timed levels, except obviously in racers. I can stand timed sections, if appropriate, but once past them, I want to be free to roam and explore levels.
7) Points of no return within a level. Again, like for point 6, I like to calmly explore, particularly after clearing a level of foes. Like for point 6, I can stand limited use of them, if appropriate.
8) On-rails, except in some old 2D classics.

Point 1 and 2 made me hate Prince of Persia: Sands of Time, because they are particularly pesky combined and on PC with mouse and keyboard they're even worse.
Point 5 made me hate Myth III, also as it didn't allow to zoom-out enough to comfortably control and place troops on wide areas, let alone doing it quickly enough in real-time.
Point 7 made me a little disappointed in some Tomb Raider levels that I'd have liked to explore after defeating them, while luckily these games, unlike PoP, implemented automatic camera quite well.