I voted bacon, but I actually prefer bacon on non-toasted bread. I like a lot of sandwhich toppings, but I go through stages where I will only really eat this or that, then I'll get bored and move onto something else. At the minute I enjoy a nice bit of pate.
I also really like to get two slice of toast, butter both, then put Philadelphia or other cream cheese on one slice, and then jam (preferably strawberry or apricot) on the other, and then put them together. Seems strange, but it's really good.