In the past, before I started having issues with dairy, I'd have gone with cold pizza. During undergrad, I'd have probably gone with pop-tarts.

These days, I prefer making hash -- when I bake potatoes, I'll bake a few extras, so in the morning:

1. preheat a large skillet
2. cut up potatoes, some bell pepper, onion, whatever other interesting is in the fridge (sausages, leftover steak or corned beef, etc.)
3. add oil to pan, start browning the potatoes
4. While waiting, get dressed, check e-mail, etc.
5. flip the potatoes and add the rest of the stuff to warm through.
6. season w/ whatever's on hand. (seasoned salt, adobo, salt and smoked paprika, etc.)
7. If desired, crack over and egg or two and cook for another minute
8. serve

If I have leftover rice, I'll make nasi goreng.