I'm weird, I prefer the cookie and don't like the cream
Except in cookies and cream ice cream or a milkshake otherwise I never eat Oreos unless I'm desperately hungry (which happens not uncommonly when I'm at work in a hospital, but I always go for the Lorna Doones first)
Without milk I twist them open, eat the creme, and then finish the cookies. I put "other" on the poll since I couldn't find that option there. With milk I dunk them whole.
Dipped in plain black coffee (very underrated, the bitterness of black coffee compliments to overly sweetness of the Oreos perfectly) or a big stack of them submersed and broken up in a glass of milk eaten with a spoon They’re also good in any kind of ice cream. And I like to use them in Oreo m&m cookie bars I bake sometimes