If you're budget-restricted, your best bet is this Columbia Raincoat. It's a popular item, while not very pricey. Another smart option is this Topshop Duster Coat. While the price is not very high, be sure that this product will become a valuable addition to your wardrobe. You may also want to look at this Barbour Padded Vest. This item is not expensive either, but it will make a difference in your wardrobe.
If you can afford to splurge, then you won't be disappointed if you check out this Raincoat. It's a costly but smart option. Why not take a look at this Helly Hansen Raincoat too? Expensive, but worth every penny. And one more item you might be interested in is this London Fog Raincoat. 'Cause you deserve nothing but all the finer things!