Luffy - Gear 5th, Awakening, and whatever beyond that (new haki levels or more gears?)
Zoro - All 3 Supreme Black Blades. Dunno what's left for him.
Sanji - He already used level 3 CoA against Queen so I don't think he'll need an CoA upgrade anymore (if you don't believe me then see the explosions around and behind Queen), FS, Adv CoC/CoC coating, third and final level of Jambe (Surtr Jambe).
Zoro - All 3 Supreme Black Blades. Dunno what's left for him.
Sanji - He already used level 3 CoA against Queen so I don't think he'll need an CoA upgrade anymore (if you don't believe me then see the explosions around and behind Queen), FS, Adv CoC/CoC coating, third and final level of Jambe (Surtr Jambe).