Ann Arbor, MI
Atlanta, GA
Austin, TX
Berkeley, CA
Chicago, IL
Minneapolis, MN
Nashville, TN
New Haven, CT
New York, NY
This week's favorite is Austin. Ive been there a couple times for SXSW and had a blast. I imagine its a little different at other times of the year, but it seems like a pretty rad place. Some of the pros for Austin (illustrated by emily's amazing photographs from SXSW 2005 and 2006):
Delicious food, including Amy's Ice Cream (mmmm....guinness ice cream)

Live Music Capital of the WORLD!

bike friendly (they dont all have horns)

affordable housing (all this for $100 a night!)

even if the toilets are sometimes possessed

All of this, of course, is subject to change.