Diamondback has some of their bikes up to 46% off. [diamondback.com]
You'll need to create an account to see them, but it's free and they don't send a lot of emails. Here are some of the notable deals:
Wildwood Classic 30% off - $244.99 [diamondback.com]
Insight 2 42% off - $349.99 [diamondback.com]
Overdrive 27.5 22% off - $389.99 [diamondback.com]
I bought a Diamondback directly from them last year and am really happy with it. They shipped directly to my house, and it wasn't hard to put together. I did get a friend of mine from church to help me get it set up properly to make sure everything was adjusted the way it should be.