Originally Posted by dave in the basement
If you haven't checked out Design By Humans, give them a shot: http://www.designbyhumans.com/
They don't do mashups very frequently at all, and they have a great selection of cool shirts. Some of the shirts are quite odd, though, so consider yourself warned!
I am hooked on the various shirt of the day sites, but DBH is my favorite from an artistic and quality standpoint. YMMV, of course. Happy hunting!
There are some cool designs and the prices and shipping are way better than some of the other custom tee sites out there, although a bit more than the sites mentioned in this thread.
Do you have any thoughts on the shirt quality? They make it sound like they source their own. I tend to consider American Apparel shirts to be the pinnacle of quality as far as custom sites go. Do these DBH ones stack up?