Tsunade no doubt. She shouldnt have been in that seat in first place.
1. She let jirayia go fight Pain when she should have gone there
2. Couldnt stop Pain
3. No actions against Akatsuki
4. No actions against Orochimaru
5. I think she was in love with that Hokage Seat.(probably used Leaf's money on gambling aswell)
1. She would have done worse than Jiraiya. Jiraiya actually almost won, and even Nagato admitted that Jiraiya would probably have won had he known about all 6 paths.
2. So? Feats of strength don't necessarily make a hokage. At least she kept many villagers alive. Besides, Kakashi couldn't stop Toneri. Just like Tsunade depended on Naruto to deal with Pain, Kakashi depended on Naruto to deal with Toneri. Minato couldn't stop Obito and Kurama without dying (and making his son an orphaned jinchuuriki). Heck, I could even argue that Hashirama failed to stop Madara in the long run. Yeah, he temporarily killed Madara, but Madara was able to pull a fast one on him with delayed izanagi, and he was also able to get a bite out of Hashirama during that battle (which is how Madara got Hashirama's DNA). If Hashirama had been more careful and not let himself get bitten, and made sure that Madara couldn't use izanagi, then Madara wouldn't have gotten his DNA, survived, awakened the rinnegan, summoned the mazou, manipulated Obito, so on and so fourth, and ultimately he wouldn't have been able to cast the infinite tsukuyomi on the world years later. Hiruzen couldn't stop the Uchiha massacre. The list goes on and on. In comparison to some of the things on this list (the earth almost getting destroyed by the moon, or the whole world being placed under genjutsu because of Hashirama's failure to stop Madara), the village getting destroyed in a way that was not beyond repair seems small.
3. No actions against akautski? She made a platoon that served the sole purpose of tracking down and taking out akautski members. That was the platoon that she formed when she sent Asuma and Shikamaru and a few other people out to take out Hidan and Kakazu. She also sent teams 7 and 8 out on a mission to capture Itachi. Also, in Tsunade's defense, Konoha wasn't the only one that didn't do much about akautski until the war. All 5 nations pretty much sat silently letting akautski do their thing for the majority of the series up until Sasuke attacked Bee and got Ay pissed off enough to call a 5 kage summit (and ultimately until Obito declared war). In short, that wasn't just Tsunade.
4. She sent team 7 to that Tenchi Bridge mission to find out about Orochimaru and Sasuke.
5. You're probably right about the gambling part.
