I recently purchased the Sony 40" 1080p LCD. It's pretty amazing. It looked way better than anything else we saw at the local Bestbuy. I didn't compare it to any plasmas as I was looking specifically for a 40" 1080p TV. It works pretty well as a monitor, though the VGA D-sub input only allows for 1366x768. However, the HDMI and Component allow for full 1920x1080. I purchased the 1080p over a 768p/720p set as I didn't want to ever be able to say to myself "I should have gotten the 1080p". I wanted the piece of mind of knowing that I'm set throughout the Blu-ray/HD-DVD phase, and that I will always see those movies in their full glory.
Sony KDL40V2500 40" 1080p TV at BESTBUY
As a side note, I still think that my Panasonic projector looks better than any TV set I have seen. 9' x 5' screen 4TW!