Well, "what XXX should I buy" is always hard to answer, but the short version is the following:
1) ATI and nVidia are the two main manufacturers of video card chipsets for PCs. The market is very competitive, so cards from these two sources offer roughly equivalent value. The actual manufacturer of the cards will vary. Just as you can get PCs from many different vendors, but they all have an Intel or AMD chip inside, you can get many brands of video card but they pretty much all have an ATI or nVidia chip inside them.
2) As with any tech product, year-old technology is a lot cheaper and 75% as good.
3) If you are not a gamer and don't plan on doing 3D design work, you don't need anything special as far as a video card goes. A $50 card will be
more than adequate. Expensive card = better 3D performance, that's it.
4) If you are a gamer, you can refer to benchmarks
here to see exactly what more money will buy you.
5) Amount of video RAM is somewhat important for games. But even modest cards have 512MB these days, which is pretty much all that most games will use.
6) Video cards are frequently discounted. If you're looking to save some dollars, sign up at NewEgg.com, ZipZoomFly.com, and some of the bargain sites and wait for a good deal to come to you. Also consider eBay.
