I just use shorts and a t-shirt, and bring a small waterproof bag or satchel to keep my wallet/keys/music in if the rain gets very hard. The transition from dry to wet bothers me a bit, but once I'm used to the rain (>2 minutes usually) it's no worse than normal riding and sometimes quite nice if the rain isn't facing you.
It has gotten so bad that I can't ride in it (even here in TX) but I wouldn't want to drive in it either at that point.