16gb Black. Thought about the 32 as I have the money, but I wouldn't put that much music on the phone; I also sync regularly so any pictures or video I record would be offloaded nightly as well.
Plus, being an "ex audiophile", if I did decide to get the 32gb version, I would HAVE to pick up a pair of IEMs, which would run me another 200 minimum. I'm not too keen on going back down that route.