Chivalry: Y/N? (Probably 4 pack to get my friends in on it)
The Stanley Parable: Y/N?
XCOM Enemy Unknown: Y/N? (Without DLC)
Dishonored: Y/N?
Money isn't exactly tight for me, but I feel like I should display some amount of restraint. Maybe.
edit: ninja'd. Oh well, I guess this is irrelevant now. But let's not let a good post go to waste, hm?
Can't say anything about Chivalry at all, and I've been hearing good things about Stanley Parable, but never played it. It sounds like it might not be a very replayable game, however.
Dishonored, I have nothing but praise for. Very interesting, very challenging in the right places and with the right self-imposed limits, and generally a good combination of stealth and action. If you have a craving for stealth FPS action, this is what you should get.
XCOM, sans expansion, is quite enjoyable as well, though you honestly miss out on quite a lot without Enemy Within. Even being priced higher than the base game with the smaller discount, EW is quite worth the money, as it adds a lot. If you aren't attracted to the simple niceties of large robots rocket-punching aliens across the road though, Enemy Unknown is still a great tactical game. If you would prefer a game of turn-based tactics to stealth action, XCOM is a great choice.