Kubica or Alonso I'd say - Alonso came form the back which was impressive, and Kubica did well with the Renault which isn't really up to the spec of the top 4 teams. Hamilton did well too, as of course did Button.
I'm not sure whether to account the excitement of the race to rain - in fact, I'd guess it didn't. The rain was very limited - a light sprinkling it appeared and they were on intermediates. It probably added a bit but I would say that woulda been a good one with rain or not.