I have been to several Les Schwab's in Portland, including their Barbur & Powell locations. A couple times I have gone in with a flat tire (which I did not purchase from them) and they fixed it for free! They didn't try to sell me anything, and their service was just as fast as it was for the people who were spending hundreds of dollars on tires!
Pros: Fast, friendly service and honesty!
Cons: Some prices are higher for tires, but their guarantee is the best, so it's worth it!
more