To make one thing clear: By best I DO NOT mean the strongest but which Hokage ruled and served Konoha the best?
Hokages:
Shodai Hokage: Hashirama Senju
Hashirama managed to join clans who were at war, establish Konoha and more or less keep it in peace. His biggest problem was Madara which he didn't handle quite good.
Nidaime Hokage: Tobirama Senju
Tobirama had the foundation of village but he brought structure, education, and safety in times of war. He eventually sacrificed himself to save his team. His rules and organisations are copied by all the other villages and are still used in this time. ANBU and Ninja Academy are his legacies.
Sandaime Hokage: Hiruzen Sarutobi
Manage to keep Konoha at peace during the Third Shinobi War. Stopped Orochimaru from destroying the village by sacrificing himself. Though Uchiha Masacre happened during his time.
Yondaime Hokage: Minato Namikaze
Minato ended the Third Shinobi War and is hailed as the Konoha Hero cause he stopped Obito destroying the village. He died during that event and his reign was short but peaceful as it seems.
Godaime Hokage: Tsunade Senju
Manage to keep political relationship with other countries and improve medicine in village. Biggest flaw of her reign: Konoha got crushed by Nagato.
Rokudaime Hokage: Kakashi Hatake
Managed to recover Konoha from War, pardoned Sasuke, expaned the village, started improving its technology.
Nanadaime Hokage: Naruto Uzumaki
Naruto, much like his father, is considered a hero of Konoha, even before he became Hokage. The 4th war made him a hero of the world. He manageD to save Konoha (and the world) twice since he assumed office and continued on developing Konoha slowly making it a big city rather than a village. Established friendly connections with other Kages.
So, who's the best and why?