Hard to choose really. I'll just ramble about a few things that annoy me.
EA - The way they're marketing SW:ToR. Putting a digitally distributed game up for pre-order is all good, but limiting the number of pre-orders (of something which is only limited by bandwidth) and charging a stupendous amount of money for the "privilege" of pre-ordering is one mighty dick move. Still, it seems to be working, proving that we gamers will happily throw money at anything that has a popular IP or developer name on it. (I'm not bashing ToR, it's just we barely know if it's going to be worth a pre-order yet)
Capcom - Cancels long awaited game, blames fans. Releases incomplete game, releases "patch" as a new game.
Ubisoft - Their DRM, I'm all for trying to prevent piracy but having to have an internet connection for offline gaming is just silly.
Activision - It would be nice to see an innovative game from them, but there's plenty of other developers out there so I'm not particularly bothered about Activision. I suppose one genuine gripe would be that they've done nothing (except blame Sony) to stop hacking on the PS3 version of some earlier CoD games.
That's all I guess.