Optoma HD72: By far the brightest. Best picture in best mode (after color calibration), with very rich colors. "Brilliant Color" technology lets you easily adjust image quality to compensate for room and personal preferences. Very good black levels and shadow detail. Very imited placement flexibility, 
although long zoom throw lens probably will let you place on rear wall. Needs that basic color calibration more than the others. Two year warranty.
The image of Gandalf was shot on the Optoma HD72.
The InFocus IN76 is our unknown, so look for our review and update in a month or less.
Of the two more expensive projectors I mentioned:
Epson Cinema 550: Brightest of the LCD projectors and close to the Optoma HD72 in that regard. Excellent room placement (not quite as good as the Sanyo). This projector is a more expensive alternative if you need that placement flexibility AND need an especially bright projector.
Sony VPL-HS51A: The most expensive of all of these. Very sharp, and the blackest blacks of all. Pricing, though, is typically at least a $1000 more than the Sanyo or Panasonic. The Sony, like the Sanyo, is not particularly bright.
Summary: Personal preferences are going to be a key determining factor, unfortunately very few people shopping for projectors in this class will get to actually see one or more of them, let alone side by side. For my money, I lean toward the Optoma overall, for its picture, and brightness, if the room issues work out. I can tell you that I have recommended at least once each of these four projectors, to people I know, based on their individual requirements.
Take your time, and choose wisely. Again, all of these award winning home theater projectors will produce a truly impressive image for their rather reasonable prices. -art
