IT's all depends what the wrestlemania card looks like
If this is indeed taker'S last match, then you have to go with his match as the last match of the show especially if my idea happens and he'S facing Cena for the WWE title.
Outside of that, you go seth rollins vs HHH which is pretty much confirm at this point but that's a middle of the card match in my opinion.
Lesnar vs Goldberg might not happen so if they are split up and the rumor is true that they want to do Goldberg vs Roman Reigns maybe for the universal title but they could use that match as a headliners or at less one of the mid card main events.
Lesnar as lost a little bit of his luster so his match isn'T important as much as it was last year.
Owens vs jericho, while a great matchs might be a good main event for the end of the first hour especially since you got a pretty good idea how the match ends because of the fact that jericho is leaving after mania.
And Aj vs Samoa Joe if that's really the direction they want to go for mania is a great match but not great enough to be headlining the biggest show of the year.
So If i'm the booker for mania and i look at all the big matches on the card, my pick for the match that should headlines wrestlemania would be either CEna vs taker for the wwe championship or reigns vs goldberg for the universal title but i would probably go more for the cena vs taker match.