I use the Topeak mountain morph and reckon it's the best pump I've ever had. It's fantastically well made, and easily dismantles if there's a problem, or if you want to clean it...
The best thing is that it has a short hose to the valve, which means you don't risk damaging the valve, or pulling ot off by accident. It also operates like a small track pump, with a small fold out foot, which really takes the stress out of pumping.
Only possible downside is if you want to mount it on the bike, it's not terrible but the pump is a bit large for a mini one. Personally I carry it in a bag so it's not a problem.