Greek yogurt is a great source of protein. Sweeten it with Splenda or something similar and add some sugar free pudding powder for flavor. Fage Greek yogurt has 23 grams per cup and 130-150 calories.
Quest protein bars are *very* tasty and an average bar is 180-200 calories and has 20 grams of protein. They're also high in fiber at 18 grams each (72% of daily recommended amt). I buy mine online. I would recommend getting the sample box of their original line (12 flavors) to figure out what you like.
Cottage cheese is also high in protein (20 grams/cup, I think). My sister adds Fiber One cereal to it with a couple tablespoons of chocolate chips.