The first item that will help visibility when driving is a product called Rain-X. It comes in a spray bottle that you use to apply the solution to the window, then polish it away with a microfiber towel. It will leave a wax like barrier over your windshield causing rain and snow to slide off.
Bosch Icon wiper blades. These wiper blades form to the curve of your windshield creating a tight seal to remove the maximum amount of water on every swipe. It is also designed where it applies an equivalent amount of pressure throughout the entire blade eliminating streaks left behind on the windshield.
3000k temperature replacement fog light bulb. The standard bulbs in your car do not cut through fog, rain, or snow very well. They actually reflect off of the fog and don't allow you to see through it. The 3000k temperature bulbs are gold in color and are able to cut through fog the best with out reflecting light and increase your visibility the most out of any other colored bulb.