FlatOut 2, on sale for €4,99 on Steam.
It's a great arcade racing game where you can wreck your car and all the other cars in spectacular fashion. I had installed it illegally for a mini LAN party with some friends (I don't normally download illegally but I didn't feel like buying it for that one weekend only). Now I want to play the single player game so I figured I should buy it.
There's also FlatOut Ultimate Carnage which is just FlatOut 2 with better looking graphics, but my PC is too old for that so I'll have to make do with the regular version, which still looks pretty good.
EDIT: and it runs like a dream! I like how my system doesn't even meet the stated system requirements, but that's only noticeable in the intro video, where the sound stutters. For the rest, I have it running on 1024*768*32 with all details except draw distance set to max (no ant-aliasing and anisotropic filtering though, but you don't really notice those effects in a racing game anyway) and it runs very well with a very fluid frame rate and I think it's a good looking game. Looking forward to do the career mode.