If you are on a tight budget, this Brixton Hat will fit the bill. It's a foolproof choice, while not very expensive. In this price range, you can also consider this Club Monaco Hat. It's also a popular item and won't break the bank.
For something in the middle of the price range, you're in luck with this Rag & Bone Beanie Hat in stock and waiting for you. You are guaranteed to love this piece.