I) Gunther
The Ring General earned the right to face a world champion at SummerSlam after he won the King of the Ring tournament. It was already announced that the winner of the King of the Ring tournament would be challenging a world champion at the mentioned event. As of now, Gunther is favourite to challenge the World Heavyweight Champion since he is in Monday Night RAW.
But recent rumors suggest that he might move to SmackDown in order to challenge Cody Rhodes for the Undisputed WWE Championship at the biggest party of the summer. There are even rumors that he might set a huge upset by defeating Cody at the event. This dream match has not occurred yet but it is definitely happening at some point and we can surely expect it to be a five star match.
Whatever the match Cody Rhodes gets, it is most likely to be the main event of SummerSlam and it is surely going to be a classic, much like most of the matches of Cody. All the mentioned possibilities for the event can enter The Ring with the current Undisputed WWE Champion to provide a Summerslam classic. Of course, there are possibilities that someone else might get this big honor. But the only thing we can guarantee is that Cody will produce an amazing match at the biggest party of the summer.