#2 Shane McMahon
Shane McMahon has been at the centre stage of both RAW and SmackDown for a while now. He is on a winning streak at the moment and has won matches against top stars such as the Miz and Roman Reigns. He does the same with the help of his stooges namely Drew McIntyre, Elias, the Revival; and sometimes even B-team, and the team of Bryan and Harper helps him out.
Shane could use his backups to protect him from potential threats. The audience might not like the segment if Shane would get crowned with any other singles championship, but 24/7 title won't have such effect.
#1 Roman Reigns
Roman Reigns is on a dream run after his return as far as the crowd reactions are concerned. WWE Universe has looked past his minor inabilities and has cheered him throughout his comeback run. Reigns also brought an edge to his character, which definitely helps connect with the WWE Universe.
Even if Reigns isn't anywhere near the title scene, whether it's the top championship or the mid-card titles, he is the biggest full-time superstar in WWE.
A title run from Reigns would erase the title's impression of a jobber's title. Sometimes, the title makes a superstar, while sometimes, it's the other way around. In this case, Reigns could uplift the title and could bring it to the forefront of WWE TV.