In that last topic on Subway and whatnot, I made it kind of obvious on my views on Subway sandwiches. (I don't like them).
But, as for my favourite or preferred sandwiches which I make, then I enjoy a few;
Ham + Cucumber + Tomato + Mayo
Chicken (or Turkey) + Lettuce + Mayo
Peanut Butter + Cream Cheese (possibly my favourite?)
Not very creative, but with fresh ingredients (in the first two primarily), they can be absolutely lovely.
Also, I prefer White Bread to Brown Bread or Granary Bread.