I prefer Pepsi, but at restaurants, I order Coke. I do this because it’s more likely that the restaurant serves Coke and not Pepsi. So instead of setting myself up for disappointment the majority of the time, I instead ask in a way that will either get me what I ordered (satisfactory), or a pleasant surprise.
Here’s how it goes down when they serve Pepsi:
Me: I’ll have a Coke.
Server: I’m sorry, is Pepsi okay?
Me: Even better.
See, I’m happy, and so is the server, who went from feeling sorry to relieved to having a happy customer.