Re: What Nvidia card to choose for a Multimedia platform?
First get a separate TV card as tvin functionality which is offered by some card isn't supported on Linux. Next to that you can basicly get any card there's on the market. I would get a card from the Geforce6 or Geforce7 series it doesn't matter that much from which series you will buy one as the GPUs are more less the same. The main difference between all the different Geforce6/7 cards is in the clocks of the GPU/memory and the number of pixel/vertex units. The higher the clocks / the more 'units' the faster the card.
A simple card would be a Geforce 7300GS which costs I guess about 70 euro / USD. It is good in 2d and can also be used for playing games although not at the highest resolutions or with tons of eyecandy. If you want something better take a Geforce 7600GS or GT which are about 100 euro / USD more expensive. The GS is most of the time silent and is slower than the GT model. If you want even more performance you can get a Geforce7900. For info on performance search for a review on the web.
If you don't need much 3d performance just go for a 7300GS.