McDonald's Shamrock Shake. It's not just straight-up mint, it's got a good hefty vanilla undertone that softens the mint and makes it more warm and homey. It also has what tastes like a hint of lime that gives it just the right zest. I can't get enough of them when they're selling and probably the only reason I go to McDonalds at all.
Do piƱa colada's count? They have a sort of "milk" in them. . . I like mine with rum of course. If they don't count, then:
Chocolate would probably be my second favorite but I like my chocolate flavors strong and dark and most places can't provide that so if I can't get one of the two mentioned above, I just skip milkshakes all together.
Vanilla's ok I guess but everything's flavored with vanilla, even chocolate, so I find it very plain and bland. It's too overused as a base flavor for everything.
Strawberry I hate the most. Most strawberry shakes taste very artificial and artificial strawberry flavor is made from the a**l gland secretions of beavers. (
True fact)