I have never been a huge fan of leftovers, but with cooking for 2, we ALWAYS have something to put back in the fridge. By "tweaking" the original meal, even by just a little, I can get excited about eating it again.
Original meal: pasta with homemade tomato/bell pepper sauce.
Leftover 1: I threw together some quick meatballs and simmered them in the sauce (not a huge change, but different enough that I didn't find it boring) = spaghetti and meatballs (Joe's favorite food).
Other recent leftover transformations:
roasted chicken --> chicken salad and chicken pot pies
gravy --> chicken pot pies
chili --> frozen in a muffin pan (then I removed the lumps and threw them in a ziplock in the freezer) so that we can heat up individual servings when we want them!
chopped up kale and leftover leek greens --> kale, chorizo, potato soup
Some leftovers DO get better after sitting in the fridge. The chicken cacciatore with olive rice that I made recently was one of those, as is my chicken marsala, and most soups. Thanksgiving leftovers are still pretty awesome the next day too, I'm excited for next week!
Now if only I could find something good to do with leftover mashed potatoes...