I like these combinations:
Peanut butter (natural), oats, honey, banana.
Strawberry, blueberry, honey, oats.
PB and chocolate syrup (or drink mix, whichever I have).
"Fruit mix" (has like mango, strawberry, etc...found in frozen food isle), oats, ice, and maybe some golden raisins.
The possibilities are endless. Sometimes I just open the fridge and grab random stuff out of it and toss it in the blender. Pretty much any kind of fruit would work. I always try to add oats, especially if I have some steel cut oats (600 calories per CUP). Most of the time my protein flavor of choice is vanilla, as you can easily overpower it with other flavors to hide it if needed (like with chocolate syrup).
Another one I like is making a REALLY strong cup of coffee and adding it. Yum!