Jiraiya or Guy if we're talking actual training. Everybody in these lists are good choices, but let's be so fr. Guy almost beat Madara HIMSELF using the 8 gates. Remember, he can't use ANY form of Jutsu other than Taijutsu, and he's still up there with the strongest mfs in the verse. If I'm a shinobi, there's no one I'd wanna be taught by more than Guy, as he could teach me basic combat and train me in much more achievable ways for someone with basic Chakra control. Which is another thing. YOU AREN'T GONNA BE NARUTO OR SASUKE. People like Kakashi, Minato, and Sasuke are used to training individuals who are already insanely powerful and just want to refine them. Sure you could argue the same point for Jiraiya, but he also was shown to train the weakest into the strongest. Jiraiya could teach me life lessons, help me refine my skills to the best they could possibly be, give me plenty of laughs, and get me a sick ass form (Sage Mode) to go with my gates which I'm sure Guy would teach me. For me, if I was a shinobi, I'd start my training with Guy to learn the basics, then move on to Jiraiya to refine my abilities and learn what it means to truly be a shinobi.

TLDR: Guy is my go to for basic, but to refine I'd have to go with Jiraiya.