Sage Mode is technique is that allows the user to utilize natural energy from the surroundings and use it as their own. Sage Mode was used by several Characters in Naruto, and Hashirama was one of the strongest at using it.
Here are 5 Characters who had a stronger Sage Mode than Hashirama Senju.
5. Madara Uchiha
We begin with Madara Uchiha. Madara absorbed the Senjutsu chakra from Hashirama, and used it amazingly well. He fought all 9 Tailed Beasts blinded, but was able to defeat them all. Later, Madara became the Jinchuuriki of the Ten Tails, which gave him a heightened form of Senjutsu, known as the Six Paths Senjutsu.