A tried and true classic- PB&J. You really can't beat it. Takes minutes to make, minutes to eat, minutes to clean up. And it's delicious. Can't beat good ol' PB&J.
PB+J is great, but it must be made with Skippy and Smuckers. For me, anyway. I'll never forget being in a gourmet restaurant of some sort, and the PB+J was "organic homemade peanut butter from who-knows-where with wild lingonberry jelly on a lightly toasted fancy schmancy bread"