-Raiton goes to Sasuke. Not debatable. Most versatile due to Chidori and variants and most powerful by far due to Kirin. Lmao. The fact he can control natural lightning alone grants him this spot without contest. Even Sasuke's Chidori is stronger than any other person's Raiton in the series by far.
-Suiton goes to Kisame. Also not debatable. Water Dome says hi. GSB says hi.
-Katon goes to Sasuke due to his natural Uchiha Katon and Amaterasu/Kagutsuchi, which is officially classified as Katon. Not debatable either.
-Doton goes to Onoki. Kitsuchi may have the strongest Doton, but most of the other techniques he can perform Onoki can perform as well. Onoki has Rock Clones, Kitsuchi doesn't. Onoki also has Added Weight and Light Weight Boulder Jutsus which are far more dangerous than the Mountain Sandwich.
-Fuuton goes to Danzo. He's easily more versatile with it then Temari though he might lose out in power. Don't want to give Naruto "best user of this element" because of a single technique.
None of these are even debatable except Fuuton and maybe Doton tbh.