Just bought a X-mas present for myself and my Xbox; a Panasonic PT-AE700U LCD-projector, featuring true native 16:9 (widescreen) 1280x720 (720p) resolution display, I'm very impressed with it so far to say the least, great picture for a great price. Saved some money too by buying a 200x200centimenter roll-up drape called "Tupplur" from IKEA for $30 to use as a screen, this drape is designed to not let any light through it and one of the sides of it has the exact same characristics as a real 1:1 gain home-cinema screen. I managed to get a 89" display out of this solution (but the projector can deliver up to 170" display if your screen is that big and the room is dark enough), and if I darken the room I can run the projector in low-power/economy-mode so I can not hear the fan inside it at all. Highly recomended! Note though that this projector model is currently being phased out as it's being replaced by the newer PT-AX100U model (which features all the same functions but higher ANSI Lumens and Contrast Ratio), so the PT-AE700U can be found for a few more months at a great price.
For anyone wanting a high-end but relativly cheap reciever/amplifier and speaker solution for the Xbox I can also recommend the THX® Certified 7.1 surround speaker system I have for my Xbox:
Creative GigaWorks S750 speaker system and
Creative Decoder DDTS-100, which features Dolby® Digital EX, DTS®-ES, Dolby Pro Logic® II (movie and music modes), and DTS Neo:6 (cinema and music modes) 5.1, 6.1 or 7.1 surround sound decoding. I all I can say is, amazing sound! ...tough if you have a smaller room or a smaller budget then
Creative Inspire P7800 (7.1) or
Creative Inspire P5800 (5.1) should be enough to impress you and your friends when combined with
Creative Decoder DDTS-100. All got great reviews and can compete heat-to-head with much more expensive home-cinema recievers/amplifiers and speakers.