#4 Batista
'The Animal' was not very well received by the WWE Universe when he came back and won the Royal Rumble in 2014 but most of that negativity came due to Daniel Bryan not being in the Royal Rumble match. The great thing about professional wrestling is that you never say never and Batista seems to acknowledge this philosophy too, because, despite the fact that he quit the WWE in unfortunate circumstances, he has never ruled out another return and has openly stated multiple times that he is open to return full-time.
So, if WWE wants to shock the world and receive some mainstream media attention then they definitely need to bring him back one final time and give him the send-off he deserves. Entering the Royal Rumble at No.30 would definitely blow the roof off the place and could lead 'the Animal' to win the whole thing, rectifying the mistakes that led to his departure in 2014.
A win for Batista would be iconic and could give the fans a dream match against 'the Beast Incarnate' at WrestleMania 34.