Projectors are nice but unless you have a basement I wouldn't want it as my 'main tv' in the living room. I watch too much stuff during the day and while, yes, you can see it during bright light, it's nothing compared to watching a crt/plasma/lcd. LCD in fact shines best during the day, others (especially projectors) will suffer. Plasmas have a very reflective screen that can be a problem at times, and projectors will wash out details (in which case why go 1080p?)
For movie screenings done mostly at night, or gaming sessions projectors are unbeatable if you have the space. I'd just use it as my 'second' tv or bring it out for parties. The bulbs are also a cost factor you must bring into it.
LCDs have the bonus ability of being a really good PC monitor, although both plasma and projectors can fulfill this role as well to a lesser extent. For my money, I went plasma. For most of the same reasons that Smooth Groove dictated.
Definitely go with a plasma. I had a 50" 720P Panny plasma but I got sucked in by 1080P hype and switched to a 1st gen 46" 1080P Sony LCD. It was a terrible mistake.
Despite the higher resolution, the Sony LCD put out a far inferior picture. It's only advantage over the Panny was a less reflective screen.
I've since switched back to a Samsung 58" 1080P plasma and it's the best TV I've ever owned.
That said, if all you can afford is a really cheap plasma, I'd probably go for LCD, especially if you still watch a lot of SD stuff (like wii.) Plasmas need a really good scaler as everything is scaled to their display ratio. Pioneer was the leader in this area, but both Panasonic and Samsung make good plasma panels as well. I'd save my money for that.