in Tucson, i like to keep it ghetto... Ajo Bikes (Ajo and Benson Highway). Ordinary Bikes is cool, but sometimes too busy with the all the college dunces... in which case I've had great dealings with Nick at Fairwheel Bikes. He is a shredder MTBer who knows fixed gear, even though they don't seem to stock as many fixie parts.
As far as I know, there are no "boutiques" in Tucson and I'd love to keep it that way. Tucson is still old Vans, cutoff thrift store pants and slayer t-shirt.
Cheers to BICAS, our bike co-op... the definitive anti-boutique.