I've been meaning to post this in a while, but the consistently best tempura I've had in the Bay Area is at Mutsu in San Mateo. Other Japanese restaurants seem to think of tempura as an afterthought, but Mutsu gets it right. The ingredients and batter are always fresh, and it's expertly fried by their resident tempura guy. The only thing that was missing was the grated daikon.
It ranks right below our favorite tempura bar in Roppongi.
Any other places for good tempura?