When I used to work in Chicago, I visited the Chop House and enjoyed their porterhouse very much; in its favor is the fact that it's the only major steakhouse in Chicago that dry ages its steaks. The other places there (Gibson's, Morton's, Sullivan's) left me less than impressed with their beef and aging methods.

My favorite city for steakhouses, hands down, is Seattle. The Metropolitan Grill and El Gaucho make for a potent duo (and I haven't even visited the Buenos Aires Grill).