Minato is the best hokage if anything.
Hashi may have protected the village, but he protected it from a monster he created due to his lack of of will. Had he just been firm against his brother and insisted Madara become the first hokage, things likely would not have turned out like this. They were the best of friends until this pivotal moment, and hashi failed hard to the point where right now, It may cause the destruction of the world. He also didn't ensure that Madara was dead at the end of their battle, which also would have prevented all of this.
Tobirama ****ed up in not letting Madara become the first hokage like his brother wanted, but pressured hashi into changing his mind. He had to take on the duties of hokage, because he didn't let Madara become the first hokage. Other than this we don't know too much about Tobirama's reign as hokage, other than he made the Uchiha the police force (arguably a bad thing), and was an extreme hypocrite in the way a hokage is chosen. Tobirama was firm that their should be a vote for who the first hokage is, yet he solely picked Hiruzen to become the third hokage. Such a thing is hypocritical and bias.
Hiruzen let all the underhanded things go on for decades from danzo, he failed in making a compromise with the Uchiha, he allowed Orochimaru to live and eventually let him destroy a large portion of the city and kill him, and the list goes on. While Hiruzen was a powerful kage, he definitely did not make the wisest decisions for the city.
Tsunade is definitely the weakest hokage overall (not physically weakest of course). She couldn't defend her village from pein when the time came, and even though she used most of her chakra on katsuyu to keep everyone alive she still let numerous people die, including Kakashi. But in the decision making department she can arguably be said to make the best choices out of the other kages. I'm not going to argue that way, but mainly her choice in allowing Naruto to fight has not only saved the city, but has saved countless lives and perhaps the world.
Now for Minato the best of them all. Overall we don't know too much about Minato's term as hokage, though we do know some things. His strength, skill, and intelligence were all great. He was able to fend off both the kyuubi and Obito, something no one else in the entirety of the world could have ever dreamed to have done at the time. Relationships with the Uchiha were clearly amazing at the time period, because Kushina thought Sasuke's mom was trustworthy enough to let her know how her pregnancy was doing. While Minato was hokage, it would seem that most everything in the village was perfect. So during Minato's time as hokage he protected the village diligently (The village was only able to be attacked by someone near invincible). He protected the city from a TBB, saving everyone's lives, he fended off both Obito and the Kyuubi, and his greatest and his riskiest feat of all. He made the choice to give the kyuubi to an infant child. This choice he made as a hokage changed everything. He saved the village from having to be attacked from the kyuubi again once it was revived by doing this and he gave the leaf village a ninja capable of saving their village and creating strong relationships with other villages, like the village of the sand. Minato's sealing the kyuubi in Naruto was a decision that would come to save large populations time and time again. Minato's choices as hokage and his strength as hokage put him as easily the top leader of the leaf village.