#1 Kevin Owens
There could only be one winner for this. Kevin Owens is the only full-time wrestler who held the Universal Championship for a number of months and defended it on a regular basis. H basically topped this list by default. Owens was only the champion because of Finn Balor's injury, but the circumstances surrounding his victory were shocking, to say the least.
The Prizefighter won the Universal title in the most opportunistic way possible, as Triple H turned on Seth Rollins. Since then, Raw became the Kevin Owens Show (with Chris Jericho). He constantly delivered entertaining segments alongside his best friend, Y2J.
While every title match had some sort of interference, they were still really entertaining. The best match of Owens' reign came at Royal Rumble 2017, when he defended against Roman Reigns in a violent no disqualification match, with Jericho suspended in a shark cage above the ring.
The reign did end prematurely at the hands of Goldberg in a multi-second squash, but not before some legendary moments of pure entertainment. The best one was the Festival Of Friendship, the night when Owens savagely turned on Jericho.
Kevin Owens did not need to do much to become the greatest Universal Champion of all time, but his reign w indeed a highly entertaining one.