TVs...

So what can you guys offer in the way of advice for buying a HD TV?

The bigger the better. I've got a 58" wide piece of wall to mount the TV on. I'm not sure how "big" a TV that gets me, although this one is 52" and 56" wide so I'm guessing is probably the kind of size I'm looking for? Although that is kinda confusing cos I thought TVs were measured across the diagonal and that'd mean it'd only be 20" tall? That sounds kinda too small tho?

But I guess the main issue is all the other fancy numbers? Contrast and stuff?