ATI/Nvidia card for HTPC

I'm looking for a suitable video card to be used in a HTPC system. I will probably use a Windows software program but would like the option of dual booting a Linux distro. Currently, Nvidia seems to work best (the drivers aren't as problematic) but that could change later, perhaps?

Anyway, I have read that Nvidia's video graphics cards has 'tearing' in htpc pvr computer systems but I don't know how bad this is or whether I should consider this a factor in my decision. I might want to play the odd game, too.

I was originally considering a 8800gts card so that it could be used for potential HDTV video and it's also probably good for video editing/converting etc. But, if Nvidia has a 'tearing' problem when streamlining/recording video, I might have to reconsider. I know there is a Purevideo program for Nvidia but I'm not sure how much it helps.

It would be great who knows about these issues could reply but I'm appreciative of any reply advising or suggesting any options.

Cards looked at and considered so far:
ATI X1950XT
Nvidia 7950GT, 8800GTS 320/640MB