I have stainless steel & ceramic & plastic. I really like that ceramic bowls come in cute designs, and they look nice in the kitchen and stuff.

Gonzo has a ceramic food bowl and water bowl.

Fozzie has a stainless steel skid-proof food bowl and a really thick, hard plastic skid-proof water bowl. It's plastic coated in something or other.... but it's really nice, chew-proof and not the typical plastic.

And they have a huge ceramic water bowl inside, and a huge stainless steel water bowl outside.