I've always had a thing for well-designed mugs - I love picturing myself enjoying a cup of coffee or good tea from it. Here are a few I've been loving lately:
Bodum French Press Travel Mug, $10 at Bed Bath & Beyond
Penguin Classics Mugs
Orla Kiely designed mug
Pantone chip mug (Did you know? The guy who invented this system graduated from RPI!)
Boulder Mug, $10 at Urban Outfitters
CMYK mug and Everything Happens for a Reason mug, from CafePress
I <3 Jim mug, $8 at Urban Outfitters
Tea cup, $14 at Anthropologie