Mainemilitary.com
I've used Maine Military Supply for finding several surplus and survival related items. They have an eclectic supply of various different items (note I have never purchased ammo or firearms from them) at good prices. Many hard to find items. I have bought fuel cans, gas masks, sleeping bags, firestarters, etc.
An example of their customer service follows: I ordered an ECWS sleep system with cover from them, as their prices were MUCH cheaper compared to CTD or Sportsmanguide. It was advertised in used but very good condition. When I recieved it, I noticed several sewn repaired areas on the bivy cover that I was concerned would make it not as watertite as it should be.I emailed MMS, and even though they could have said "it's surplus, deal with it," they offered to exchange the item for one hand inspected to ensure it didn't have any repairs. The replacement was like new (didn't look issued at all).
Sometimes shipping can be a bit slow going out (this is an actual store, not a wharehouse). Other than that, A+, never had a problem with them. Be sure to check their closeouts.