CBid is my go-to.

But here's where I have all you guys beat - I work with a BOTL who shops online all the time, and is a sucker for every good deal that comes along. He tells me about the really good deals and if it's something I want, I'll just go in with him on an order. All the benefit, none of the hassle. It's nice having a personal shopper who works for free

For pipe tobacco, I usually use P&C, but that's pretty much past tense - I did an inventory of my tobacco cabinet a few months ago and concluded that I have a couple lifetime supplies of mostly pretty good stuff, therefore I'm not buying anymore.