Strictly speaking by the Ocular Power, I consider Obito's to be the strongest (both defensive and offensive Kamui, Kamui Portals though it seems that this is the technique that cause his eyes to bleed/Susanoo since his eyes had the potential to awaken it [Don't think it'll be PS though. PS was the resultn of Six Paths chakra])
Followed by Itachi's MS (Amaterasu, Tsukyomi, and Susanoo [This isn't talking about the character himself so I won't think of Itachi's stamina and it's not like his MS consumes more chakra than Sasuke's for example so I consider his better than Sasuke's due to Tsukyomi [If you look at his eyes even once, you'll.be caught in Tsukyomi and won't be able to break free if you aren't an Uchiha. If you avoid looking at him, you'll be surprised when black flames suddenly spawn on you. Susanoo is also a defence that doesn't hinder either of these abilities and actually works well with them offensively as well. [I won't count Totsuka and Yata since they aren't a literaly a part of the Mangekyou/Susanoo. They are simply weapons that were found and equiped onto his Susanoo])
Followed by Sasuke's MS (Enton, Amaterasu, and Susanoo, some say he had Tsukyomi but now I begin to question that [Forgot who it was that found out one eye uses Amaterasu while the other controls the flames])
Followed by Madara's (Susanoo, I don't know of his other abilities)
Followed by Shisui's (KA is very useful but the reason I brought it this low is because it's once a decade [Since this is just talking about the Mangekyou alone, his speed won't be taken in consideration, obviously])