I purchased one of the Gore Xenon jackets from performancebike.com. It was a bit pricey, but it works very, very well in the rain. I didn't wear appropriate pants or shoes on a cold rainey commute, but I had my jacket on. My top stayed nice and dry and the temperature was well metered; not too hot, not too cool. It breathes better than I thought, and it's small and light enough to crumple up and throw in the bag.

I also have to give props to whomever it was that suggested wool jerseys from woolistic; I purchased a long-sleeve jersey and wool shorts and I absolutely *LOVE* them.