If you're on a thrifty budget, this A.P.C. Coat will fit the bill. It's a fail-safe choice, while not very expensive. In this price range, you can also consider this A.P.C. Coat. It's also a popular item and won't break the bank.
If you're looking at it like an investment piece, then you won't be disappointed if you check out this Giorgio Armani Coat. It's an expensive but smart option. While you're at it, also have a look at this Narciso Rodriguez Coat. Yes, this item is expensive, but it does not mean it's not worth it.