Ninjutsu: Orochimaru - no contest, he has a vastly larger arsenal of jutsus at his disposal.
Taijutsu: Orochimaru (Minato*) - why are there so many people saying Minato? I don't even remember Minato throwing a single punch or a kick, all he's done is fight with knives, and even those moments are short-lived. Orochimaru was toying with 2T Sasuke, engaged Hiruzen + Enma in hand-to-hand combat and a 3-tailed Naruto. Minato is never taking this category, *unless a FTG blitz somehow counts as taijutsu.
Genjutsu: Orochimaru - zero genjutsu feats from Minato easily gives Orochimaru the win here.
Speed: Minato - no contest.
Chakra reserves: Orochimaru - current Orochimaru should be leagues above alive Minato when it comes to chakra reserves, seeing how he has a Hashirama DNA body and absorbed his own chakra back from Kabuto. We've never even seen Orochimaru out of chakra.
Inteligence: Debatable - Orochimaru is overall more knowledgable than Minato, though the latter thinks quicker on his feet. It's a tie, imo.