This list is a work in progress - too many stamps, too little time!
The Greeting Farm. If you like cute rubber stamp and digital images with big heads, you've hit the jackpot here. BONUS: These images are excellent for Copic coloring.
Hero Arts. The name says it all!
Inkadinkado. Gotta love these stamps - lots of variety and good quality. (They're also carried by Michael's and JoAnn's, so grab your 40%-off coupons and get shoppin'!)
Leavenworth Jackson. Looking for something fresh and just plain cool? Check out Ms. Jackson's rubbah stamps of excellent manufacture and price. BONUS: Killer images of Alice in Wonderland original illustrations by John Tenniel. (I own these, and they make me Very Happy.)
Lili of the Valley. Can't say enough good about these stamps! If you like to color beautiful images, it doesn't get any better than this!
Penny Black. Another leader in the industry! They have elegant, cute, fun, and totally terrific stamps, papers, and stickers!