This t-shirt cracked me up:
Grandburo Honesty - Rumplo, A Place for T-shirts
I dunno why. I guess just the irony of it. I'm sure the designer meant for his shirt to be a parody of itself, but it's still great. Especially since so many people probably see the shirt and don't get that.
Some of the comments at the bottom of the page are pretty interesting too. I especially like the one at the very end by joepemberton, he says:
This should read "Design is better at lying than advertising will ever be."