So was considering getting an awesome TV

The one we have now is pretty old school; and I like buying assets after a big poker win so at least if I lose everything I still have some stuff to show for it :>
Soooo... any advice on TVs?
Desires:
- Something around 40"
- I have a preference for LCD over Plasma, but don't really know why. Does it matter too much?
- Something I can plug my computer into and play media
- Is it possible to get one that I can stick an external HDD in via USB, and play media files off etc?
- I don't think I'd want to spend more than like $4k if possible.
Cheers.