The sales guy and mechanic at Summit Bicycles in San Mateo were nice when I went there to ask about installing a headset. Because of their nice demeanor I brought my bike back and they actually finished it sooner than they estimated. But that's the extent of my experience with them. They are at least on the Peninsula side... I'd go back if the need arose.

I also like the mechanics at Pacific Bicyles in SF. They have always been helpful when i needed small bits and pieces for my bike that I either broke or lost. There is one guy that seems like he has an attitude (older balding/greying guy) but I think that's just the way he looks. Once you talk to him he's very nice. I bought a used wheelset on the net and brought it to them to replace a bent bladed spoke. He said that he'd have to order a new spoke but asked if he could check out the wheel first. So I walk around the store and when he gave it back he had repaired the bent spoke and trued the wheel, saving me a few bucks and time instead of replacing the spoke. I really couldn't tell it was previously bent. If I ever get the $$ to buy a Cervelo, Bianchi or ?? I'll definitely check them out.

EDIT: spiduhman got his name... it's Darcy. Really cool guy!