Unless it is one of the electrical components, I go to BikeSport (next door to BevMo). Friendly bike knowledgeable staff, reasonable rates and located just a little bit off the BG/missing link so it’s easy for a bike rider to get to. http://ilovemybike.com
There’s also the “JRA Bicycle Shop” at 8318 8th Ave. NW. (Corner of 84th) They often have a discount coupon in that monthly deals envelope that is mailed out. They saved me a bunch of money by just fixing the things that weren’t working rather than doing a full tune-up which is what I thought my bike needed when I walked in. They have received very good reviews.
Check them out: http://www.jrabikeshop.com/
(Note, they are closed on Mondays.)