Egg whites really are the best thing, but they need lots of help, imho. One of my favorite breakfasts at the moment is an egg white and black bean wrap, topped with a tb of ff sour cream, some chopped cabbage and a giant pile of pico de gallo (or salsa). It's delicious, under 300 calories and has lots of protein and fiber. It's also absolutely giant. By the time I've piled all the veggies on top, I have an entire plateful of food. It's great
The only egg white snack I do is a 1/2c egg whites and 1/4oz cheddar cheese on a whole wheat muffin. 210 calories (high for a snack, so it depends on your calorie allotment; for some people that will be breakfast instead), but with 4g fiber and 18g protein. It's a snack that sticks to the ribs, and because it has melty cheese on it, it feels like a treat.