They only sell bikes in the Trek family (which includes Gary Fisher and Lemond), but on those their prices are very fair. They'll order any model in the lineup within days; customer service is great and they are fantastic about supporting the product--if things go wrong, they make them right. Unfortunately they don't have rentals or demos for serious test rides, but they will let you ride around the block.
Pros: fair prices, great service, product support
Cons: no rentals/demos