All those are good additions to your milkshakes. The chocolate/peanut butter/banana was probably my most used combination. I actually keep bananas in the freezer. Easier if you peel them before freezing. I'd snap them in half and decide if I want half, a whole or even more depending on how much milkshake I wanted that day.

Also added whey protein, frozen cherries, raspberries, blueberries, etc. coconut milk, mint, vanilla extract, ovaltine, etc.

Hmm, a chocolate stout milkshake might be pretty good. (Yes, we do hear that alcohol could be bad for you. I'll leave it to others to decide if alcohol in small amounts is ok for them. I don't know how much of a contributing factor a beer or two on a weekend evening could possibly be, but I still enjoy them on occasion. If you're worried about it, don't drink them at all, but I'm guessing by your username that you might appreciate the many different styles of beer out there.)