Sorry I can't support Ebay's BS and politics, so I refuse too use them if at all possible.

I've used..

www.skdtactical.com
www.triadtactical.com
www.tacticaltailor.com
www.eagleindustries.com

I watch a lot of the for sale forums at places like:

www.snipershide.com
www.ar15.com

and here of course!

Really depends on what I'm looking for. A lot of the consumables I try to buy locally, but I'm going to have to start buying bulk ammo online, there just isn't any place in Denver aside from Wally World that has a good price. Well at least not that I've found