I think they're pretty much of a muchness, can't think of a brand of inner tubes that I wouldn't bother with (although those ones pre-filled with Slime seemed like a waste of time). I'm liking Continentals right now, but probably because CRC always seem to have the Presta valves in stock.
One thing, since weight weenie-ing, I've noticed big weight differences in some of my tubes - 265g for some no-name tube versus 87g for those Maxxis Fly Weights. I've got to say, based on a couple of XC rides with the Fly Weights, they are a lot tougher than you might think - no punctures, and it's not like I'm one of these guys that float over the terrain... I'm not exactly a lightweight either (13.5 stone).