Hmmm close, but I'll go with Djokovic on this one. Murray gave him all kinds of fits (though so did Verdasco for Nadal), but the length and brutality of that final edges it out for me. Vs Nadal, Novak had to go to the threshold of tennis, physically speaking that we've seen in such a big stage. Fed basically gave away the 5th set to Nadal, despite playing better that whole match, so it wasn't competitive until the end.
The tour needs Del Potro to be back and playing healthy