beetiger

I've only used CafePress, but I've been very happy with their work. Some of my favorite (read: usually worn weekly when the weather permits) shirts came from them. The designs are fading somewhat after several years, but not badly, and the fabric has held up very well. I found the sizing to be pretty standard for the regular (not women-specific) T-shirts, long-sleeved T-shirts, and sweatshirts. They are not "fannish sizes" though.