I prefer any vanilla protein powder, since I like to doll up my food and increase the protein grams. That's my daily goal--get 50 to 70 grams of protein, then relax and enjoy the food I eat the test of the day.
I can add peanut butter powder, vanilla and believe it or not, sno-cone flavorings! I love malted milk, chocolate, and other sweets.
I also get unflavored and add savory seasonings or a dab of tomato paste. There are so many packets of dry flavoring mixes, I never get bored. Cold, heated, stirred into soup or sprinkled onto veggies or salads--It's all good!
Your imagination is your only limitation.