Naruto: Hero of the village before he became a hero of the world. The peace the world now enjoys (during Kakashi's tenure as Kage) was won through Naruto's actions.
Hashirama: He defined the shinobi world for generations. Designed villages for people and clans to live in. Instead of them being warring tribes with no nation.
Minato: War Hero and Village Hero during the Kyubi attack. Hiruzen was alive and still in good shape but he was useless during the Kyubi's assault. Minato also gave his son the key to winning the wars and conflicts of the future.
Tobirama: Aside from his prejudice of the Uchiha, he did try to help them by channeling their emotions in to something constructive. He also created FTG, Kage Bushin, Edo Tensei and presumably other OP jutsu. I think it was Tobirama's students who screwed up his inherited will I.E. Hiruzen, Danzo and the Konoha Elders.
Tsunade: Not offensive but at the same time did nothing to really stand out. She had her shot to defend the village but it was Naruto he defeated the assailants while Tsunade slipped in to a coma.
Hiruzen: Uchiha Massacre, Hyuga Affair, Danzo's dirty dealings, Orochimaru's horrible experiments on scores of people (including 40 babies), and the invasion of Konoha by the Sound and Sand all happended under his watch. Every event was telegraphed to Hiruzen in advance and yet Fodderuzen did nothing to preempt them.
Kakashi: Why are you even Hokage? You're a seat warmer and chief.