We are using an Optoma EZPRO 750. The device is no longer manufactured by Optoma who discontinued its production last year, but it still can be found new from many retailers.
That is not, however, the projector I would buy if I had a choice and a decent budget. We got that one off of e-bay simply because it was one of the more attractive models which met our minimum specs and was available at the time. We got lucky on our lamp and unit. You are not likely to be as lucky.
If money is really not your major concern, I would recommend the Dell2300MP. It retails for $1349, brand spanking new, at 2400 Lumens it is daylight bright with a contrast ratio which is among the best in class. Best of all - its XGA native mode at 1024x768 so your picture will be sharp and have vibrant color.
At a throw distance of 5'7", depending on the zoom factor you employ, you will get a diagonal resolution of between 36" and 43" for that projector. That is about average for a DLP at that throw distance.
The brightness, contrast and reosolution are exceptional on this projector. You will have a very fine piece of hardware for your money - very nice for Home Theatre use as well if you plan to employ it for that purpose.
For a SVGA projector, meaning only 800x600 resolution, there are a lot of other options.
The Dell 2200MP is 1200 ANSI and will give you 39" to 47" at the that throw range. The Dell's price is once again - AWESOMELY attractive and probably makes this the most favored choice of gamers looking to get in on this technology. Currently, Dell is selling the 2200MP for $719. That is incredibly cheap folks.
For a brand new projector, that's pretty hard to beat. You'd be doing very well to get a used projector off of e-bay for much less than that.
The Dell 2200MP has to be a front-runner for a lot of people on ENworld.
If image size is your goal, the Sony VPL-DS100 can give you an image from 48" to 59" or so at that throw range. It has a street price of about $1,000.00-$1,100 - and it's at 1200 ANSI.
When given a choice, I would choose brightnesss over size, any day. For images larger than 44" or so, I would want a XGA - not SVGA projector. Your image is going to become visibly pixellated at times if you go for the Sony.
A final reminder: If you look to buy your projector used off of e-bay, you need to be VERY aware of the fact that your lamp is definitely used. How used? You don't really know - no matter what the seller says.
What you must remember is that it is $300-$400+ to replace your lamp in a DLP projector. One can be penny wise and pound foolish buying used.
An unknown used projector for $600-650 or so vs. a brand new 2200MP from Dell for $719?
You don't need me to tell you where the smart money goes on that prospective purchase.