Out of everything we sell my favorite is the Choose Books t-shirt because it reminds me of high school and the 80s, specifically of George Michael's hair in the 80s (and I'd like to special effect the Jitterbug video so that it looks like he's wearing our T-shirt. Whatever happened to Andrew Ridgely? (Maybe I should put a question out on Unshelved Answers.)
Also love the library schooled T-shirt. The font is just small enough that folks have to take a good look to read it, and then they just look at me like, "What?" Love it.