The NEC HT1000 is getting rave reviews; if you haven't checked feedback on AVS forum I'd suggest looking there (in the "Digital Hi-End Projectors - $5000 USD MSRP and Up" forum). It can be had for around $4200-4300 plus $150 rebate. It's not 16:9 native but most people seem to think the slight loss of resolution is minor compared to the great color, black level and other picture aspects.
The Sanyo PLV-70 is a light cannon LCD, also highly thought of by most. Same price range as the NEC, depends on whether you like the strengths/weaknesses of DLP vs LCD.
Another option you might want to consider if you like DLP, though a little above your budget, is the Toshiba MT8 which has the HD2 16:9 DLP chip. Same unit as the Infocus 7200 that's getting raves, but a bit cheaper and maybe easier to find (once it comes out in a few weeks)... can probably find it for around $6k.
CRT is still the king of the HT room. The digital technologies are closing but aren't there yet. If you are critical of your viewing then you can get a pretty good setup for $5K if you do some shopping.