Imagine, if you will, the ne plus ultra cheeseburger: thick and dripping with cheese, topped with grilled onions. That's the name of the game at Town Topic, a shoebox-sized KC institution where businessmen squeeze in next to construction workers at the counter during the lunch rush and orders are served up by efficient waitresses. If you're smell sensitive, stay away: the dominant scent here is grease with a note of nicotine.