Maybe G. carinata var. verrucosa... Gasterias hybridize easily and can be very variable in form, but that's my best guess.

I agree with Jen. Most Gasterias I've seen are unnamed hybrids, but this one is both common and a bit more distinct than the others. It pups pretty well, and has been around for a long while (my Grandmother had one 25 years ago).

For many pics of Gasterias and their hybrids, check out the link. Some of yours just might be there, pictured along the right side near the bottom of the page. Happy searching. (Might take some time to download.)

Al

Here is a link that might be useful: Gasterias