Sure there are cards you can use, but what you choose depends on factors you have left out. What kind of CPU does this computer have, dual core or quad core? What model Dell, and what form factor(mini tower/SFF/desktop)?
Let's assume some things for now. One, a low profile card would be the best option since it'll fit in most cases. Two, that computer doesn't have a lot of power so only cards that don't have a 6 pin pci-ex connector should be considered. Three, since the computer is older you should get either a used card or a new card that uses older technology so that the card will be compatible with the older motherboard bios.
I'd say then something like an AMD HD 7750 or Nvidia GT 730 DDR5 fit the requirements. You could probably find an older AMD card for less money, but the 7750 is the oldest card still supported by AMD drivers today. The 730 is still for sale lots of places new, in case you'd rather buy a new card. Whatever you get, DDR5 vram is critical, don't get a DDR3 card.