Team Jiraiya. Jiraiya's the big reason he didn't blast Nagato's head off, so there's that. The combative side of what he taught Naruto was pretty lackluster though given the amount of time the two spent together.
Imo, it sort of feels that Bee & Hachibi would've been his best teachers had their teaching not been limited to controlling Kurama's chakra. They never simply gave Naruto a set of instructions and fucked off. They actually elaborated on them beyond saying shit they knew Naruto wouldn't get like the 8:2 ratio and engaged him when they were competitively stacking rocks. He spent like an evening(maybe 2 days idk) with them and came out a beast that could form rasengans with his chakra arms.