While I do like ketchup (on the side, though) with a (cheese) burger, I do like them with lettuce, tomato, and mayo or miracle whip. One of my favorite ways to enjoy a burger is simply to top it with crumbled bleu cheese during the last little bit of grilling. This is also known as a "black and bleu, or blue" burger. Also, If I’m not putting it on a bun, I like it with A-1 steak sauce. That is the only reason that I buy A-1 steak sauce- never for steaks! I insist on mustard on a hot dog- absolutely no ketchup, please, but cannot stand mustard on a hamburger.