Dunno about "best", but I've had good luck with my Filzer Mini-Zee Pump with Gauge. It bears an eerie resemblance to the venerable Road Morph, but having never used one I can't make the comparison.

On the flip side, I am strongly considering a switch to CO2 this year, but only if they work in the cold. I commute through the winter and the thought of fixing a flat in subzero temps makes me think I'd like to do it as quickly as possible (i.e., a new tube and a CO2 inflator). Does anyone know if there's a temp limit for CO2 (high or low)?