i have a dell something or other model it is 2500ansi lumens and i can watch tv on it during the day as long as the sun is not shining on the screen. it cost me $750 and was the best investment on my home theater. i bought an actual projector screen for $150 a few years back, MUCH better than a sheet or bare wall.
a few things to look for when purchasing.
ansi lumens of 2500 or better for bright settings.
get a projector of the same aspect ratio as your computer monitor if running from a pc(you can clone the 2 rather than having a stretched desktop)
if you get a projector with bad display(black/ white levels) you can adjust the gamma in your computer to get it right. if you are running a cable box or game console it will look like crap. my old acer and benq was this way. the dell however had a really good picture out of the box.
