What TV card to buy?

I've recently moved into an apartment that provides cable TV. Since the apartment complex doesn't seem inclined to shut off the service and give me a discount, I'd like to take advantage of it...and rather than buy a television, I thought a TV tuner card would be a good idea and provide me with more functionality. Unfortunately for me, I don't know a thing about TV or video broadcasts, and I'm afraid of buying something overpriced, incompatible, or both. Basically I'd like a PCI card I can put in my desktop system (Gentoo) that can connect to the coax port in the wall and allow me to watch TV on the computer. Anything else is bonus; I've already got an nVidia card (FX 5500) handling the VGA monitor. What would be best to buy in this situation?