Hiruzen, the powerful, kind, elderly man theme got me in the first part and I've always liked him a tad. His mistakes only make him more human to me, which I like
Minato. He was by far the coolest. He always did what he believed was right. He went out of his way for other's as much as he could. And he's one of the fastest, if not one of the strongest.
Tsunade easily. The other hokage are quite boring. I do like Tobirama though. And I have nothing against Hiruzen. Hashirama is quite annoying and Minato too because of his perfection.