Board Thread:Naruto Discussions/@comment-25343176-20150612124722/@comment-5273810-20150612145645

Madara during "life" was in the same league as Kurama(with no Jinchuriki attached). Compared to Hashirama who was roughly 2x that of Kurama(with no Jinchuriki) Hence why Madara + Kurama in the Battle of the Final Valley was so close a fight as with that enhancement Madara truly was on par with Hashirama.

But to answer your question. No one during the 1st Hokage's time was in his league and no one after that either(up to the Madara debut the bit after that I'll discuss in a second). Madara with Rinnegan, Wood Release, and Kabuto's enhancements is around the power of when Madara and Kurama fought Hashirama at Final Valley. So that is one. Naruto(once friends with Kurama) is roughly on level of Hashirama. Sasuke with Rinnegan is also in the same league.

When Kakashi got DMS(Double Mangekyo Sharingan) he was also buffed to Hashirama levels albeit it was only temporary since it was only when Obito was in his subconscious(should also note So6P chakra was also involved).

So in summary only 4 shinobi after the creation of the Hidden Villages have been in Hashirama's league. Madara(with Rinnegan, wood release, and Kabuto's enhancements), Naruto(from partnership with Yang Kurama and beyond), Sasuke(with Rinnegan), and Kakashi(with DMS for the brief time he had it).