1. all women in the game are stupid or helpless
2. war, war, war and more war (don't we get enough on the nightly news?!)
3. cat people
4. dialog in-game outweighs play time (final fantasy, blarg)
5. you must endure an hour of cut scenes before getting to play
6. no female characters in a game that touts massive character customization options (Brink)
7. Only on console, must use a controller (carpal tunnel problems = controller is a no-go)
8. Cold, callous characters who are on a rampage for no particular reason
9. Being "on a rail" and not given the opportunity to explore the game world and go on tangents
10. arriving at a level or boss that is for no reason 100 times harder than anything you had experienced to that point in the game, and having to try over and over again to beat it. (aka having to memorize a sequence from a walk-through online and then execute it quickly and perfectly to beat it)
?and just to put a little positive spin on this thread - things that instantly make me want to play or finish a game:
1. powerful female characters whose dominant feature can't be described by a single letter.
2. someone took the time to make the characters lovable, a la Pixar
3. cheeky humor that makes you laugh out loud (Grim Fandango, Psychonauts, Portal)
4. games that allow non-hardcore gamers an easy/story mode and a chance to have a great experience in the game without being a master of keyboard controls (Thank you Fallout!)
5. good user interface! If the game looks great, put the polish on the UI bits, tutorials, online forums, websites, documentation, etc too please, these are part of the game experience.
6. games that build and support a community of happy players
7. a community of people in the game that is positive, encouraging and makes your experience awesome, especially when you come in as a newb.