Linux compatibility - what would be a good fit?

Ok so I'm looking at video cards that would be a good match for linux based OSes like OpenSUSE and Debian. I want something that would fit in $200 and be able to play some games in Windows when I feel the need to not study for work / be naughty.

Although AMD/ATI have improved support by leaps and bounds, NVidia GPUs still have the best/seamless driver support you can hope for in Linux.

As far as I know, ATI drivers are better, but they are in the middle of a closed-to-open transition, so things are messy right now. Their bleeding edge cards are still closed source, and unstable.

The nVIDIA drivers work quite well, but are closed source if you card in newer than 7-10 years old.

I'd go with nVIDIA unless you stick with Richard Stallman.