The burger at the Bristol Lounge in the Four Seasons is the best I've had anywhere, any time. Everything about it is perfect: the meat is first-rate, it's cooked exactly as I ordered it, and the roll is fresh and great. (Don't underestimate the importance of that last part.)
Count me in as one who can't understand the fuss over Bartley's. The bohemian atmosphere is certainly pleasant and unaffected, but I find the burgers to be overcooked and generally unexceptional.