I've bought from Bike Bandit, Ron Ayers and Service Honda. I've been happy with all, but I'd most likely go back to Service Honda.
Ron Ayers and Bike Bandit have better Web interfaces than Service Honda. If you're looking for OEM parts, you need to get the part number from Ron Ayers and then copy them over to Service Honda to get the price and order. I've not found a way around this.
Ron Ayers takes a long time to ship. Bike Bandit never has a lot of OEM parts in stock. Bike Bandit sends me advertisements about themselves every three or four days (I should probably unsubscribe). Service Honda has good stock, doesn't take too long to ship, and they have the best prices of the three.