Boost makes an amazing shake it's called "Boost Very High Calorie". It's 530 cals and 22g protein in a little 8oz shake. They're not cheap but extremely effective.
I've been drinking protein shakes for like 20 years now, so they don't really bother me. But they're sold in vanilla, chocolate, and strawberry. I've done vanilla and strawberry and think they were both really good, no problem chugging them down at all, and at only 8oz it's not an issue.