I have a few that I love from Inked, the two player lord of the rings being my favorite but legendary being equally awesome. For this order I got Death Angel, Resident Evil LCG, and Shadowrun (made my own real quick). Pretty much any deckbuilder works well and has one available. Sometimes they can be found on DeviantArt too, though they are tougher to find.
Wow, those Elder Sign playmats sure are something else. I didn't even realize that Inked did custom mats. I looked at their site once a while ago and saw a Great Wave Off Kanagawa mat that I thought I would want during a sale, despite not needing a CCG-style mat since I don't really play many card games. I thought I might pick it up during this sale but a cool Elder Sign mat is very tempting to me as well.