Hotdogs, fairly basic: just mustard and ketchup. I also prefer to nuke 'em rather than boiling or even grilling.
Hamburgers, also fairly basic: cheese, pickles, mustard and ketchup, and Ihave to put them on in that order, don't ask me why. Sometimes, I'll put bacon on them (before the cheese), and sometimes barbecue sauce (instead of mustard and ketchup.) Other than the pickles, keep the veggies off and just have them as a salad on the side. Except for the onions. Throw those things away.