My only actual collections is Fiestaware, Amberstone. It started out as a fluke then became an obsession... You could find this stuff for like 5 cents at yard sales. I only lack a few hard to find pieces. Ashtray being one of them!!!
But there is a teapot and coffeepot that I don't have either. I don't know if I will ever complete my set. It's been fun casually looking though. It's a reason to go to antique malls anyway!
It was made for grocery store give-aways. Most people consider it junk, but, it was made by fiestaware...it was the last time the "old" fiesta molds were used.
I should look on e-bay. I've never really checked there before. Amberstone Fiestaware Fiesta Dinnerware on TexasCooking.com
That link has a few examples of what I collect!