I still use a Zoom G2.1u, which I have been very impressed with. I now mainly use it for the odd bit of flange I need in a track, or a tiny bit of compression for my cleans, and it works wonders. I don't rely on it for distortion sounds (any more), as I now have a Peavey 5150-II which does the high gain stuff beautifully :)
I know that many, many people have a grave disliking of multi-effects units, but I have to say that I would still buy another Zoom G2.1u if mine were stolen, as it's easy to use, doesn't cut sound when switching between presets, and actually doesn't sound bad!
I used to use it for everything (distortion included), and found that the guitar-zoom-amp setup where the amp does the distortion and I just use the zoom for a bit of "signal conditioning" works much, much better.
I have no reservations recommending this unit, but with the caveat that it needs to be used properly - that is, use it to give yourself a whole load of effects which you use sparingly (for which you'd need 5 or 6 individual stompboxes, costing hundreds of pounds!). Don't buy one if you're looking for "the unit above all others", because such a thing doesn't exist!
Most importantly (which I didn't do, but got lucky!), try before you buy!
Roo