Seed Savers Exchange is a great place to buy rare, unique varieties of vegetable seed.
The seed catalogs starting arriving a few weeks ago.
Pinetree Garden Seeds is my favorite. They are inexpensive and offer some rare varieties as well.
It's best to order early before varieties sell out. Last year there were several vegetables I wanted to grow but I waited too long and they sold out. (Red Noodle Yard-Long Bean, you will not elude me this year!)
Totally tomatoes is the place to go for your tomato seed. Every variety imaginable.
So while I have my nose stuffed into a catalog drooling over 15 varieties of eggplant in a rainbow of colors, hundreds of varieties of tomatoes, and more, the snow is swirling outside. Let it snow... it gives me time to prepare for next year's planting.
I've found a great source for wholesale seeds as well, which is great, since I plan on growing even more vegetables next year.
HPS Horticultural (wholesale prices & large quantities).
Hps is the parent company of well-known seed companies, so you're basically ordering from the well-known companies show below, only in larger quantities with wholesale prices:
All the vegetables I grow are heirloom varieties. Heirloom seeds are old-fashioned varieties that have been around for at least 50 years, breed true to form (meaning you can save the seeds from a vegetable and grow it again next year), and they are not genetically modified.