Shake Shack.

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Over the course of the last year, I've embarked on a grueling mission: to taste and rank every shake on Shake Shack's menu.Just as I was getting my appetite back, the chain announced three new summer flavors, so I knew what I had to do: It was time to revisit the shake rankings.Shake Shack has six main milkshake flavors that are available all year, as well as three or four limited-edition flavors at any one time.My ranking of 16 Shake Shack flavors, each made with frozen custard, includes classics such as chocolate and vanilla, as well as limited-edition shakes like the Dubai Chocolate Pistachio, which was introduced last summer and brought back this month due to popular demand.Here's how I ranked them all, from my least favorite to my favorite.Shake Shack did not respond to a request for comment from Business Insider.

In last place came the strawberry shake.

The strawberry shake.