Another vote for Stan's rims. I don't have the exact figures at hand, but my set of Stan's Crests (29er) with 32-hole XTR hubs, double-butted spokes, and brass nipples built up at ~1600 grams. They've done just fine in all sorts of terrain, including some pretty rocky stuff in Maryland and West Virginia, and they're easily repaired no matter where I am. I could have gotten them lighter, but weight wasn't my primary goal with these.