I have two...bacon, egg & cheese with the bacon extra crispy on white bread. As asort of "comfort food" sandwich, tuna melt on toasted white bread. Since I love every type of cheese out there, I'm not picky about which type for either.
Mm, you have good TASTE in sandwiches, janshares.! I think my very all-time favorite is ham and provolone on (very) slightly toasted rye with pickled onions, tomato, lettuce and Italian dressing. I am also a huge Reuben fan!
I had a favourite some years ago - blue stilton cheese with horseradish sauce on wholemeal - but have progressed beyond that combo now! I go for smoked ham on wholemeal with lime pickle (a hot Indian pickle with tangy slices of lime) washed down with a good brew of strong tea!