www.alloy.com
and
www.fossil.com
http://www.80stees.com/
http://trippintees.com/
http://www.cottonfactory.com/
http://www.nerdyshirts.com/
http://www.tshirthell.com/ (really BAD)
http://www.threadless.com/
(I somewhat of a t-shirt freak)