Unskippable cutscenes.
If I just spent 15 minutes whittling down a boss' HP with a sliver of health remaining only to get killed by a rogue dust particle in the air that hit me in the eye and killed me, I don't want to have to sit there and watch the previous cutscene every single fucking time.
Protect/escort missions.
I can't stand them. I'm horrible at them, and unless the person I am escorting has some form of protecting themselves, then they should just stay where I found them until I've killed every single thing between here and where I'll need to go.
Half-arsed multiplayer.
Dark Sector is one game I can think of that's guilty of this. Not sure about the PS3 version, so I'll skip that and split-screen has been done on a few PC games, but it's uncommon.
On the Xbox 360 version, the only form of multiplayer you have is Xbox Live. No system link, no split-screen. However, on the PC version, the only form of multiplayer is a LAN option. No online, no split-screen.
Does not compute.