The Wanhao Duplicator 4X seems to be pretty popular with people on the 3D Printer Tips, Tricks, and Reviews Google group. If the build size weren't as small as it is, I'd have probably gone for it myself. I went with a Rostock Max V2 kit instead. Nearly complete, though I've been working on it at a snails pace due to back problems, it would probably take an average person about 2 days.