Sorry, didn't mean to come off rude, a question like that is never a waste of time. It's just that I get asked this question a lot, and it's stated in every deviation. If you specifically asked about the kinds I would have thought you had read the comments.
There are a lot of polymer clays out there. Some are more expensive than others. I will tell you what I use. I use a mix of Prosculpt, Fimo and Kato clays. Here are a few places you can shop for clay.