I didn't like jaraiya because of the way he treated women, as *** objects. So bad to the extent he had a 13 year old boy look like one to appeal to his sexual interests.
But he was fine otherwise, especially with his serious moments and with tsunade, right before he left.
But I'd have to say iruka, the nice, older brother figure to naruto. He was respectful and was the first to truly care for naruto, even though the beast in Naruto killed his parents, and most people would have hated him for ignorant reasons, but iruka was too mature for that.
Though I should mention iruka is a shit character, and jaraiya is far better written.