I'm a big jerky fan. Beef, turkey, ostrich, salmon... whatever. Also dairy, especially cheese. Those little laughing cow cheese triangles have 35 or 50 cals and are lovely w/o a cracker or bread. Also the baby bells are somewhere around 75 calories. I eat a lot of 1% cottage cheese. Often with dices veggies or sliced fruit.
After workouts I rely on muscle milk shakes. But good old chocolate milk is about as good. I never thought I would recommend "plastic food" like protein shakes, but they definitely have their place.
Another snack that is pretty available, but a little pricier is shrimp. We have lots of options here in Southern Calif. Cooked frozen or fresh. Raw frozen or thawed. Personally I'm a bit of snob and insist on wild caught - but that's me.
2.5 years, 45 pounds later... 128ish pounds