I always liked to do liquid egg whites, cinnamon, maple lba's (don't think the flavor is available anymore), and natural peanut butter. I would also include oats if I didn't care about the carbs being included. If you are separating your fats and carbs you can leave out the PB or leave out the carbs. If I didn't have the maple lba's (syraplex) chocolate will work good as well, and if I didn't have either of those I would throw some sugar free maple syrup in.
Also you can just swallow the liquid egg whites down and be done wit it, it's not that bad when you just gulp it down lol
another option is egg white protein powder, I've never used it by itself but have combined it in a few protein powder mixes I have made