All things considered,
When discussing the worst Hokage in the series, the ones that should be taken into consideration are Hiruzen Sarutobi, Tobirama Senju, and potentially, Tsunade Senju. While the general consensus is that Tsunade has been the worst Hokage to ever appear in Naruto, that is far from the truth.
Tsunade's aversion to blood is a massive disadvantage to her endeavors. Considering that the Hokage are expected to defend their villages (usually being one of if not the strongest member among them), her phobia reduces her ability to fight effectively and attend to her duties as a medical ninja.
As has already been established, the weakest Hokage of Konohagakure is between Kakashi Hatake and Tsunade Senju. In fact, both Kakashi and Tsunade are quite close to each other in terms of strength in Naruto. However, their fighting style differs a lot from each other.
He is by no means weak and can hold his ground against tough opponents. Whether it be his ninjutsu, taijutsu, or shuriken jutsu, Kakashi has mastered them all.
Despite this, she pales in comparison to Kakashi Hatake. Kakashi is a very fast, and shrewd shinobi, so for him to let Tsunade hit him in the head is preposterous. Furthermore, Kakashi's offensive powers, such as Kamui, far surpass that of Tsunade's. If the two ever fight, Kakashi would emerge as the victor.
During his lifetime, Hashirama Senju was never defeated and no person managed to surpass him. Hashirama was armed with the incredible Wood Release, which is one of the strongest Kekkei Genkai in existence. It allowed him to tame tailed beasts and crush a full-body Susanoo.
Hashirama Senju – The First Hokage
Now, you know why he was rightfully known as the God of Shinobi. Being the first reincarnation of Ashura, the power levels of this man were off the charts. He single-handedly captured the eight and nine-tailed beasts and fought against Madara with Eternal Mangekyō Sharingan.
Tobirama is the most handsome hokage.
However, Kakashi was shown to be a ninja prodigy even before he gained the Sharingan, meaning the statement of Kakashi being weaker without the Sharingan is an unjust assumption. Analyzing his current skills and achievements reveals how strong he truly is, even without the visual jutsu.
Jiraiya is a ninja from the village of Konohagakure trained by Hiruzen Sarutobi, the Third Hokage. He becomes known as the "Toad Sage" due to his training under the Great Toad Sage in the field of Senjutsu (仙術, lit. "sage techniques"), enabling him to summon toads as allies during battles.
The Ninth Hokage (第回消防シャドウ, Kyuudaime Hokage) has recently become the leader of Konohagakure. As Hokage, her word holds sway over all political and military issues that present themselves regarding Konoha and its inhabitants.
Jiraiya. Jiraiya was an exceptionally competent shinobi, and he was the only member of the Legendary Sannin who could actually beat Itachi. He was trained by the Third Hokage, and learned how to use Sage Mode while training with the toads of Mount Myoboku.
Feared as the Clan Killer, Itachi had an incredibly high level of control over his Sharingan and the Mangekyo Sharingan. Kakashi, while stronger than him at one point, couldn't compare to his talent later on and was defeated by him within a matter of seconds.
With the dual Mangekyo Sharingan, Kakashi would be able to overwhelm even Pain. Between the space-time ninjutsu that allows, the full Susano'o at Kakashi's disposal, and the Copy Ninja's notorious intellect and strategy ability, Kakashi would likely be able to conquer Pain with relative ease.
Obito Uchiha is one of the main antagonists of the Naruto franchise. He is a member of Konohagakure's Uchiha clan who was believed to have died during the Third Shinobi World War, his only surviving legacy being the Sharingan he entrusted to his teammate, Kakashi Hatake.
Abilities. Like his son, Sakumo was a gifted shinobi praised for his talents in the ninja arts even by the likes of Minato Namikaze, the Fourth Hokage. In battle, Sakumo was a truly powerful shinobi, his prowess surpassing that of the Sannin.
6 Eight Inner Gates
While Kakashi isn't specifically skilled in taijutsu like Guy, he can still access the Eight Inner Gates.
The Elder declares Kakashi Hatake as the 6th Hokage.
Tobirama Senju was not fond of the Uchiha right from the Warring States Era. While his hatred for his enemies was justified at the time, when he became the Hokage, he should've been able to look at them differently.
Obito Uchiha was one of the strongest Uchiha to ever exist. He awakened his Mangekyō Sharingan during the Third Great Ninja War after witnessing Rin die. Obito's eye weilded the Kamui, a powerful space-time ninjutsu.