Sunflower Bike Shop
I love these guys. As a life long cyclist with riding experience all over the country and Europe, as well as long time member of the Lawrence Kansas bike scene, I can confidently attest to Sunflower's status at the top of the heap. Not only are they the most knowledgeable pro shop in Lawrence ( by a HUGE margin), they are one of the best in the region. People drive for hours just to have Dan, Paul, or Nate answer questions and tune their gear.
I live in San Francisco now, obviously a major hot bed for cycling in the US. Sunflower would easily be one of the best shops out here, too.