I drink smoothies often because I don't eat meat and I, also, like the protein.
In a blender, I put:
1/2 banana (see notes below)
3/4 cup milk
about 1/2 tsp peanut butter
1 scoop vanilla-flavored whey protein powder (I use Wegmans brand)
Mix and enjoy.
Notes:
I only want a milkshake-sized glass, so I use only 3/4 cup milk instead of a full cup. I get a bunch of bananas, already fairly ripe, then slice them in half and place in a baggie. Then I toss that in the freezer. The bananas will eventually turn brown in there, but it doesn't affect their nutritional value or flavor. Also, I just wipe a little peanut butter onto the banana-half, then toss in the blender. That avoids trying to get the dang peanut butter off the
side of the blender as it mixes lol.
IMO, that's the perfect blend, as the peanut butter doesn't overwhelm the banana flavor (and vice-versa).
BTW, your's sounds good, too.