If you're a thrifty spender, your best bet is this Knitted Hat. It's a popular piece, while not very pricey. Another great option is this Coal Beanie. While the price is not very high, be sure that this product will become a worthy addition to your wardrobe. You may also want to look at this Echo Beanie. This item is not expensive either, but it will make a difference in your wardrobe.
If you're looking at it like an investment piece, then what you're looking for is this Burberry Hat. It's more expensive but worth your money. While you're at it, also have a look at this Janessa Leone Beanie. Yes, this item is expensive, but it does not mean it's not worth it. You might also want to take a look at this Jennifer Behr Beanie. You won't regret the money spent!