As a rule of thumb, you're looking for something which is high in protein, high in nutrients, and low in calories (if your goals are fat loss), or simple a bit of both.
These might not all be perfect, but they are quick, simple, taste damn good, and they sure do keep you out of the biscuit tin.
1 - Protein Shakes
2 - Rice Cake with Peanut Butter
3 - Greek Yoghurt (you can even add a scoop of protein)
4 - Raw Veg
5- Boiled Eggs
6 - Fruit
7 - Protein Bars
8 - Nuts and Seeds
9 - Chicken Strips
10 - Harley's no added sugar Jelly