I have purchased 3 bikes from BikesDirect so far and am a big fan. You can order competition-grade setups at entry-level prices.
Ironically, the bikes are so great that my first two got stolen, they do look great to both the untrained eye and to those who know what each of the components is worth. The components are significantly above what you'd get at regular bike stores. I tend to have the bikes professionally assembled, but it's not really necessary - doing it yourself takes less than half an hour as all the complex parts are already pre-assembled out of the box.
My most recent purchase was a Gravity FSX Monster Eagle - what an amazing bike! Each time I ride it, I get approached by biking enthusiasts who want to know more about the bike.
Great bikes, fantastic experience. Definitely a go-to place for anyone looking for quality bikes at reasonable prices.