I have a Nitro rain suit that goes over my regular gear. Works fairly well, though it is fairly bulky. (I may have bought one size too large or something...) That said, I've found that after being in a decent rain for a while, some water gets in -- haven't figured out exactly where it's seeping in, but seems likely to be in the crotch area.
Otherwise, if I'm expecting rain for sure, especially in warmer weather, I have my Joe Rocket Alter Ego pants and jacket, which both have waterproof inner liners and have served me well so far.
Personally, I'm looking into getting one of the Aerostitch 2-piece suits this year as I need some more touring-oriented gear anyway. I hear they're pretty awesome, but not sure if there's anywhere locally to check them out prior to ordering online?