Marmot Precip jacket with hood- not as good as my Helly Hansen that got gashed. Will be patching the HH soon.
Red Ledge rain pants.
Tall Leather Thinsulate or Gore boots. Slathered with Sno-seal.
I have some midtop boots also that I'll wear but they also require gaiters if it's raining good. (see cc700's comment on rain running down shins and into shoes!)
TurfKing thermogrip gloves. They don't keep hands dry but warm enough.

On the bike: Backscratcher. Thinking about rigging up a full front fender on one of my MTBs for when I have to roll out in the torrential downpour.