I'm a big fan of snapper, lemon juice, and a nice salsa. Makes a perfect fish mean and all you have to do is sauté the fillet of snapper in the lemon juice, then add the salsa about halfway through as a glob on top. Perfect if you're poor, as the only expensive thing in there is the fish, and lemons and salsa is always lying around my house anyway.
Besides that, chinese chicken salad, which is just sauteed chicken in oil thrown on top of a salad of soft (slimy) soba noodles, almonds, cucumbers, and sometimes peas, dressed with rice vinegar. It's not incredibly healthy (rice vinegar/chicken), but it is a ton of vegetables and I think it's fucking tasty.
But usually, when I've got nothing else to eat I have a French Dip sandwich, which is probably one of the easiest things in the world to make. All you need is good bread, roast beef, cheese, mustard, and beef broth. Turn the first 4 ingredients into a sandwich, heat up the broth, dip the sandwich in the broth, eat. Not exactly healthy, but fast, easy, and tasty.