Madara is not a good sensei he used Obito for his own twisted person issues that he needed fulfilling, he never cared about him one bit.
I'll go with Jiriaya first, he's trained not just many incredible strong ninja, but he always taught them allot of morals and values in life.
Next i would have to go with Kakashi, Even though he was off to a rocky start and didn't really act as if he was much in to it, You can see now that he has created real strong bond's with naruto, he always listened and trusted in naruto's abilities and never doubted him. He also taught him allot of techniques and stuck his neck out on the line E.g, when naruto begged the Fourth Raikage to listen to naruto.
Then i would have to go with Hiruzen, He taught many strong sinobi and taught them very well, they grew up to admire and respect the village, They turned out to be excellent teachers and very respected people.
Next i will go with Minato, We haven't actually need allot of Him although to this day Kakashi still admires and respects him, he was respected by everyone he met.
Gai would have to go here he's shown interest in all his student's and always taken a person interest in their abilities, he never said to lee that he couldn't be a ninja, he trained him on stuff that he could do, always pushing and trusting in him the whole step of the way. Which is why lee is a very admirable strong Ninja, purely because Gai believed in him.
