Let's hope that this show is not main evented by John Cena vs. Randy Orton.
And I know people love Ambrose, but a midcard title unification match at Mania is an enormous step down for Punk no matter how you look at it. He needs to be involved in something big.
I think Bryan vs. Triple H is a must, and I think it should be for the title. Beyond that, I would like to see Cena vs. Taker, but I would be okay with the combination of Cena vs. Punk and Taker vs. Lesnar.
It's got to some combination of those six guys, though.