1) Hamburger - Cheddar or Montery Jack, bacon, ketchup, mustard, lettuce, tomato, and I can go either way on pickles. Bun isn't all that important, as I love to put them on my low carb tortillas, or an official hamburger bun.
2) Tuna - bleech.
3) Ham - Not a big fan of ham on it's own. Add turkey, pastrami, salami, or some other meat to it, and I am good with it. mustard, lettuce, tomato, and I'm good
4) Turkey - honey mustard, lettuce, tomato, and again, I prefer more meats with it, but I can handle turkey on it's own. adding a bit of Italian dressing is nice too. I also like cooking up leftover turkey with bbq sauce and making a sandwich out of that. mmmmmmm!!
Not a big fan of mayo on sandwiches.