I use Frogg Toggs, I think they are the Road Toad model. They pack down to the size of a football, so they very easy to carry. I hardly ever use them around home. When I first got them, I spent a week in Colorado on a certain Connie and I rode in the rain every day, some days it was all day long. They kept me very dry, the hiking boots I was wearing, on the other hand, not so much. Later on that trip I was wearing them off the bike to keep warm during a snow storm at Crater Lake and I tore a hole in the front of the pants. I was able to patch the hole and have been using the same suit for the five years since. Probably haven't had to put it on a dozen times, but it still does what it supposed to do.
They are made out what feels almost like a Tyvex-type material. They don't breath well at all, so they get pretty hot and sweaty on warmer days.
I think I paid less than $50 for the set in 2008 or 2009 and I'm pretty sure they've gone up quite a bit since then. For what I invested and how seldom I need rain gear, I've been quite satisfied.