I do. Some 32" HD Samsung with Freeview (no aerial though, no signal, argh). Only time I've used it in HD was to play Resident Evil 4 at 1920x1080 (looked awesome) and to benchmark Crysis at that res (looked awesomer).
Mostly only use it to play the Wii with friends occasionally, and watch DVDs. I'd use it as my main monitor, but my desk isn't too big so I wouldn't be able to fit my keyboard on fully; besides, I'd have to look left and right, since it'd be so close to my face.