Educational Innovations has a great catalog of science toys, supplies, novelties and activities. It reminds me a bit of Steve Spangler Science. (That said, I don't know which company came first, or even, which one I knew or first. Nor do I know how they feel about one another. I like them both. 'Nuf said.)
I've purchased from them in person, while at the New Jersey Science Convention.
I'm particularly fond of some of the fun items that add some whimsy to my classroom:
The Einstein Action Figure
Some of the products that have a greater educational purpose include:
And of course, there are the basics, like lenses, magnets, spring scales, etc.
There's a whole lot there - you'll want to spend some time exploring.