1. 3rd Raikage
2. Orochimaru
3. Tsunade
4. Susano'o (In general)
5. Kisame
Not including Itachi's Yata mirror, that's my top 5 most durable. The 3rd Raikage fought for thee whole days and shrugged off a Rasenshuriken despite it being his elemental weakness. He also solo'd Gyuki (8-Tails) and cut off one of his horns and it's implied he took a Bijuu bomb (When Naruto asks Gyuki how the 3rd got his scar).
Orochimaru because no matter what he gets hit with he finds a way to come back. He got pummeled by Tsunade, took on Naruto with 4 tails solo, probably had some sort've tussle with Manda at one point considering he never had full control, was immune to practically all poisons, now has a majority of his body as Senju, was sealed by the Totsuka blade and came back...He's the closest to immortal without Edo Tensei (debatable or tied with Kakuzu and Hidan).
Tsunade due to her Creation Rebirth technique. She's been able to shrug off blows from the likes of Madara and Orochimaru with this power active, including impalement, and even being bisected at the waist. Not to mention she's got Uzumaki AND Senju DNA and blood, so her life force is incredible to say the least. Which could also be why she hasn't died of liver damage from all the drinking she's done ^^;
Susano'o partly because of the claim to being the 'Ultimate Defense' and backing it up to an extent. We've seen it take shots from all five Kages on two occasions, with Sasuke at MS levels and Madara at EMS/Perfect levels. It has shrugged off Ay's Liger Bomb against Sasuke, a Kirin attack from Sasuke against Itachi's (unsure whether Yata Mirror took hit or not), and withstood (with some difficulties) Tsunade's immense strength under Creation Rebirth's effects, a combined attack from Ay and Onoki combining speed, lightning chakra, and increased weight/gravity. However it is not perfect. As Madara's was cracked I believe by the Kages and Sasuke's was shown to be vulnerable to Mei's Corrosive style and Danzo's increased velocity Wind Bullets.
Kisame's full potential I feel hasn't been shown despite what we've seen, as fighting Bee he was trying to lose for intel's sake. However, it doesn't change that he's taken two massive hits late in his life. The first being Bee's Gyuki Cloak lvl 2 Lariat which was enough to destroy skin, muscles, bones, and even organs. Granted his durability comes from his partner and weapon Samehada, but set that aside. Secondly, he took (as far as we know) Guy's strongest technique, Hiodura, and survived. With the properties he mentioned that Samehada gives him with stealing chakra and feeding himself with it, Kisame could in theory fight for days without much trouble.
Also, for my list, please note I'm going by what we've seen and not hype. That's why Hashi isn't on the list. Yes he has Sage Mode and Creation Rebirth, but we haven't seen much of him in combat to see the full extent of his powers. So I mean no offense to the Shinobi God.