A few years ago I ran across what I consider the most practical fishing rain wear I've seen. The company that makes the rainwear is called Frog Toggs. What makes this rain gear so practical is that it is very light, very breathable and it packs down to a fairly small size. The problem with most rain wear that you will find is that not only is it waterproof, it also does not breathe. It is like climbing into a plastic bag an sealing it shut around your body. Low breath ability means that your body is going to sweat profusely. According to Frogg Toggs their rain suits are "constructed with a patented process of three layers of polypropylene material with a center layer of microporous film. Because the pores are 20,000 times smaller than a water droplet, moisture cannot penetrate. Also, our patented seaming process eliminates needle holes and possible water entry. " Because of this unique design, "Body VAPORS ESCAPE while wind and rain stay out."
I bought a set of Frogg Toggs to give them a test run. I actually found out about them through a friend that is an avid hiker. He loves the Frogg Toggs because they are so light that they don't add any significant weight to his day pack and they prepare him for any unexpected downpours. The rain suit that I bought runs around $59.99. The material is similar to what you find a doctor wearing during an operation. It is very lightweight and almost feels like paper, yet it is very durable. After just a few uses, I'm sold on Frogg Toggs. They fit very loosely and don't restrict your movement at all. And they are so light, that you hardly feel them on you. Best of all, you don't sweat the whole time you're out fishing so you stay completely comfortable. I recommend them to all of my friends. They are nice to take along on any outing where rain showers are possible.
There is another similar version of this rain suit now available from a company named Dri Ducks. Check them out. You'll love em.