Best big flat screen under 4k

Since you specified "flat screen" models, rather than "plasma" or "LCD" models, I will assume that you are including flat screen direct-view (CRT) TV's. One of the best is the 40" Sony Wega XBR HDTV. It has a superb picture, although the set is pretty heavy (around 200 pounds, as I recall).

Given that my 36" XBR clocks in at around 250 lbs, the 40" has to be a monster. The problem isn't just weight, its unwieldy to move since there isn't anything to grab. You might think that ain't a big deal, but how many times do you rearrange your gear? Then again, it is perhaps the greatest expression of a tube based TV ever made...

After having thrown in my $0.02 based on thinking you were specifically looking at plasmas, I'll note I really am impressed by the Samsung DLPs. Just read a great thread on AVSForum on them, and apparently Samsung demoed a 1080p (yes, 1080*P*) 1920x1080 61" DLP at CES... 5000:1 contrast ratio... This, in addition to a series of new sets to be launched shortly with the xHD2+ chip that gets you to a 2500:1 contrast ratio... Might be worth waiting a bit.

I am definetly with Edesilva in the opinion of the regular CRT Tvs being way too cumbersome to move around, lest they are small in size (19".) The Samsung DLP have also caught my eyes, but I have read elsewhere about the issues that many of the competing new formats have....Plasma, LCD, DLP, back and front projections....Black level problems, burn in, bulb replacement costs etc....all in no particular order. If I consider spending around 3-4K on a next generation TV set, then, shouldn't I be expecting a long trouble free enjoyment? I had regular CRT tvs that lasted and still are lasting a good 10+ years. I wonder if these new sets will last that long, reliability wise.

There is an excellent thread on the Samsungs at AVSForum:

http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=256065

My understanding is that the downside of DLP is bulb replacement and the rainbow shimmer observed by some (but not all) people. Burn in is not supposed to be a problem, and with the newer chipsets, the contrast ratios are going from 1000:1 to plasma comparable numbers...