I wouldn't buy one. The technology isn't even close to being perfected. Also, why would I buy a high-def TV if all cable isn't high-def? So I can watch regular cable on a stretched and shitty looking screen? No thanks, I'll stick to tubes for now.
actually vivi, that's not really the case...not for me anyway. All non-HD channels look just fine on my screen.
My cousin's looks like crap. =\ Then again, as NoCal says, maybe he's just got it hooked up incorrectly. What's your setup?
That said, I still wouldn't buy one myself, yet. Even the most expensive HD tvs still look a little too pixellated for my tastes.