The Chicken Madness is without question the greatest sandwich ever, anywhere. My senior year at Georgetown, over a decade ago, I started to realize that I would be leaving DC and so I began ordering them like a maniac. Every time I'm back Wisey's is my first (and last) stop.
Had a friend going to a transatlantic conference pick me up one a few years ago right before boarding a plane back to the UK. I wept as a ate it 10 hours later, 3700 miles from Washington. Heaven.
No trip to GU is complete without a visit to this institution.
PS: I have no idea why but it's best without bacon and with a ginger ale.