I like the monthly kits sold here at scrapbook.com. There is no monthly commitment so you are free to buy the ones that you want and pass on the ones that you don't. Also, sb.c usually has monthly contests that are tied to the kits.
As a demo- I do the Stampin' Up monthly kit- My Paper Pumpkin. They just started but so far we have had a kit for cards, mini album, and more to come. Comes with everything you need other than adhesive to do the project- including stamps and ink!
If you want more info you can check out my blog or PM me.