My favorite LBS is actually a sports equipment swap shop that has various bike mechanics on duty. They all have their distinct personalities, but they're all good mechanics who don't mind me hanging around while they work on my bikes. Today I offered my strength to remove a stripped pedal the mechanic couldn't budge (I'm a big guy), and he replaced the crank arm/pedal used for $10.
I agree that having a good relationship with your mechanic is fun, educational, and generally pays off.