Mint Chocolate Chip is my favorite as well.
When it comes to shakes, that's a different story. I am extremely particular about my shakes. This is because in high school I worked as a soda jerk for a '50s-themed diner called
Galaxy Diner (used to be a small chain, now there's only one left. That pic was taken from the one in Flagstaff, AZ). I was the guy who made all the flavored sodas and all the desserts.
This included shakes and malts. And they were hand-scooped, not the soft-serve crap. On top of this, we used shake tins and shake machines instead of blenders.
Even though we had a very large variety of shakes to make from a selection of toppings, the top two most common shakes were 1. Chocolate and 2. Strawberry Banana. This means our servers entered in those two flavors of shakes a lot, and then each ticket was rung up to me.
One particular busy night a server sent me an order for a Chocolate Strawberry shake. Since I make dessert items exactly as they are listed, I didn't even question it (I would get interesting orders for things like Chocolate Cokes and what-not all the time). I made it. The server looked at it and she immediately noticed it was not the color she was expecting. "This was supposed to be Strawberry Banana." "Not according to this ticket." "Oh. Um, can you make a straw/banana real fast?"
Rather than let that interesting combination of a shake go to waste and dump it out, I kept it for myself and ate it. Eureka! I discovered the best-tasting shake I've ever encountered!
Since I controlled the tools and ingredients, I perfected it over the next few weeks. Extra chocolate syrup, extra strawberries (but keeping the correct ratio, where strawberries were the dominant flavor and chocolate was the more subtle). Extra thick. Sometimes I'd make it a malt.
If you ever run across a place that makes shakes by hand and not gets them dispensed by a soft-serve machine, I recommend giving it a try. Just make sure you let them know to use a vanilla ice cream base (and not a chocolate or strawberry ice cream base). And if all they have is strawberry syrup without actual strawberries, pass.
On a side note, having mastered the art of dessert making and having quite a few recipes up my sleeve has come in handy over the years. Especially when making a surprise visit, loaded up with supplies, to a house full of single women that I knew.