All of them?
Seriously though, depends on what you think you'd like.
I'm a fan of Chocolate Hazelnut, Morning Macchiato, Chocolate Peanut and also current limited edition Tiramisu. Apple is damn fine, but I only have it sometimes when I feel like it. Banana, Chocolate, Vanilla are a good fillers for me, something to have in-between or mixing them with other flavors. I'm not a fan of the other fruity stuff.
And do share your thoughts after tasting! Cheers!