I have a gt240, and it's a good very-low-end gaming card, doesn't require a big power supply. You wouldn't get it if you were a serious gamer, as it only delivers framerates of 20 or 30 on a lot of games. On the other hand, it doesn't suffer from first-frame-stutter as badly as the 400 (Fermi) series nvidia cards (the newer cards seem to take longer to warm up shaders on first use on linux). It's kind of obsolete now, you can buy them for $60 or so, so it's kind of hard to go too far wrong with it.
