As someone who played Aeon of Strife and its successors I dislike the direction they went with the genre (adhering to WC3's design instead of Starcraft essentially) but the first thing they should do is toss the entire playerbase into a massive oven and incinerate them all; then they can go through the trouble of improving/revamping it.
I voted shooter, only because I don't mind most other genres and most 1st person perspective games make me sick, not just shooters, watching the guys play Mirror's Edge a few weeks ago was a nightmare, that was exactly the last game I ever want to play.
Funnily enough, the Portal series is one of my favorites, don't ask, I have no explanation.
There's a lot of genres I won't touch.
- Hack and Slash/ Beat'em up
- Tower Defence
Most of those I just suck at them, and some I'm just not interested in them. I used to also hate Stealth but last year I played some mild stealthy games, and now I really like them.
Rhythm games. The vast majority are pure Rote learning, and nothing seems to bore me quicker. I don't like games that boil down to pattern matching unless you dress it up somehow (Mega Man is by and large all about patterns, but at least there's a platforming element to it, along with weapon switching, for example).
A tie for me between Sports and Fighting. I don't actively dislike them, I just don't really care for them.
Now, I find I count "Sports" as things like Madden and Fifa, as I'm alright with racing games (NFS, Burnout, Dirt 2), and I enjoyed the old Tony Hawk games. Although, NFL Blitz 2001 was amazing with a friend, as was that Snowboarding 1080 game for the N64. I also don't mind fighting in other games, like Sleeping Dogs, but regular fighting games like Tekken just don't appeal to me. I'm also not really interested in DOTA-type games.
Like I said, I don't hate them, but I'm just not interested.