If you are anywhere near Chicago, then I highly recommend visiting RobotCity Workshop right in the heart of the Lakeview neighborhood:
Additional details can be found on Yelp:
This amazing store has everything robot including kits & proper selection of components (unlike the 'Shack'). Who knew I could find an Arduino for my LoL shield (http://jimmieprodgers.com/kits/lolshield/) right here in my own backyard. Lilypads & spare AVRs were plentiful, too. The owner, Greg, said that he is going to be stocking Adafruit kits soon!
Plus, RobotCity is more than just a retail shop - they hold beginner through advanced workshops. Upcoming classes will branch out into wearable electronics, microcontrollers & PCB etching!
I posted an album of shots I took today. Hopefully, they'll get you excited to come stop by RobotCity: