Thunderbird Supply Co.
I've shopped a time or two at Thunderbird Supply Co. for beads, findings and stringing material. I love the site's variety and that, like Fire Mountain Gems, it offers bigger discounts for bigger orders. Unlike Fire Mountain, though, the combination discount doesn't apply to everything the site offers, just select items, but the prices are still pretty good.
Its shipping prices are a little higher than FM, but not enough to deter me from buying through Thunderbird. I browse every once in a while. It's been a year or more since I've bought from T-bird, but I'm just not buying beads as often as I did before I had my daughter.