Well, as far as TVs as comp monitors go, you can find various LCD TVs with VGA ports so they can function as monitors, but they're not all that good.
Additionally, most decent hdtvs today will have HDMI ports, can you can hook a PC up to with a DVI to HDMI adapter/cable. Note that most laptops won't have a DVI out port, though any desktop with a decent video card should. (not even a powerful one, just a discrete, non-integrated one)
Alternatively, you can get computer monitors with built in TV functions, and these will be much better as computer monitors, though their ability to function as TVs may not be as good. I'd recommend checking newegg.com or Dell for their lines. Any of them that are expensive enough to have built in TV tuners will be good monitors.