I'm bored, so here's my WM31. Feel free to reply with your own.

Two Hour Pre-Show

Tag Team Match
The Bellas vs. Paige & Natalya
Winners: Paige & Natalya
Length: 6:00

WWE Tag Team Championships; Tag Team Match
The Usos © vs. The Lucha Dragons
Winner: The Lucha Dragons
Length: 9:00

Singles Match
Cody Rhodes vs. Goldust
Winner: Cody Rhodes
Length: 9:00

WrestleMania 31

20-Man Andre the Giant Memorial Battle Royal
Adam Rose vs. Big E. vs. Big Show vs. Bo Dallas vs. Cesaro vs. Curtis Axel vs. Diego vs. Fandango vs. Fernando vs. Heath Slater vs. Jack Swagger vs. Justin Gabriel vs. Kofi Kingston vs. Konnor vs. Rey Mysterio vs. Titus O'Neil vs. Tyson Kidd vs. Viktor vs. Xavier Woods vs. Zack Ryder
Winner: Cesaro
Length: 9:00

Street Fight
Erick Rowan vs. Luke Harper
Winner: Luke Harper
Length: 8:00

WWE Intercontinental & WWE United States Championships Unification Match; Singles Match
Bad News Barrett © vs. Rusev ©
Winner: Rusev
Length: 8:00

Triple Threat
Seth Rollins vs. Dean Ambrose vs. Roman Reigns
Winner: Seth Rollins
Length: 20:00

Singles Match
The Miz vs. Damien Sandow
Winner: Damien Sandow
Length: 11:00

Singles Match
The Undertaker vs. Bray Wyatt
Winner: The Undertaker
Length: 22:00

WWE Divas Championship; Submission Match
AJ Lee © vs. Charlotte
Winner: Charlotte
Length: 14:00

#1 Contendership for the WWE World Heavyweight Championship; Fatal Fourway
Daniel Bryan vs. Randy Orton vs. John Cena vs. Ryback
Winner: Daniel Bryan
Length: 19:00

Singles Match
Sting vs. Triple H
Winner: Sting
Length: 30:00

WWE World Heavyweight Championship; Singles Match
Brock Lesnar vs. Dolph Ziggler
Winner: Dolph Ziggler
Length: 21:00

A bit lengthy, but after adding up all the time, and assuming WrestleMania is about three hours and forty-five minutes, that leaves around an hour for entrances, post match celebrations and whatever promos would happen. Last year's WrestleMania had about two hours of wrestling, not counting the pre-show, while this would have around two hours and forty-five minutes. Last year's WrestleMania also featured a pretty long opening promo that this one wouldn't have.

Kickoff Show:

Sami Zayn ©  vs Kevin Owens vs Adrian Neville (NXT Championship)
Winner: Sami Zayn
(If they ever put an NXT match on Wrestlemania, WWE's logic would be to put them in the pre-show)

WM 31

Andre The Giant Memorial Battle Royal
Participants: Probably almost the same guys Snoopz had on his booking of Wrestlemania 31
Winner: They'll probably go with Big Show this time cause he's big like Andre

United States Title Match
Rusev ©  vs Ryback
Winnter: Rusev

Singles Match
Randy Orton vs Seth Rollins
Winner: Seth Rollins via interference from Kane and J&J security (I'm assuming they're going to make Orton look strong, returning the month before WM to give Kane a beatdown on Fast Lane)

No DQ Match
Triple H vs Dean Ambrose
Winner: Dean Ambrose, but HHH will probably be a sore loser and give Dean at post-match beatdown.

WWE Tag Team Title Match
The Usos ©  vs Tyson Kidd & Cesaro vs New Day vs The Ascension 
Winner: Tyson Kidd & Cesaro 

Singles Match
The Miz vs Damien Sandow
Winner: The Miz by cheating/count-out/ or any dirty way of winning.

Intercontinental Championship Match
Bad News Barrett ©  vs Dolph Ziggler
Winner: Dolph Ziggler( This should be one of the best matches of the night)

Single's Match
Daniel Bryan vs John Cena
Winner: Daniel Bryan

Money in the Bank Ladder Match(this is assuming things since there's like only one major title left)
Winner: Bray Wyatt

Singles Match:
Undertaker vs Sting
Winner: Sting

Divas Title Match:
Nikki Bella ©  vs Charlotte
Winner: Charlotte(Squash match)

WWE World Heavyweight Title Match
Roman Reigns vs Brock Lesnar © 
Winner: Roman Reigns

Seth Rollins Cashes in
Seth Rollins vs Roman Reigns © 
Winner: Seth Rollins( Dean Ambrose comes in and continues his promise on interrupting Rollins' every cash-in attempt. But instead pulls a surprise by turning heel and attacking Reigns. I know some guys here want Ambrose to be the face of WWE, but if WWE wants Reigns to be the top guy - then have a mic master like Dean Ambrose turn heel)

Tag Titles
Some Heel Team (c) def. The Usos

Battle Royal Thingy
Roman Reigns wins by last eliminating Randy Orton

US Title
Rusev (c) def. Ryback

Singles Match
Bray Wyatt def. Dolph Ziggler

Intercontinental Title
Dean Ambrose def. Bad News Barrett (c) and Big E

Singles Match
The Miz def. Damien Sandow

Singles Match
Sting def. Triple H

Divas Title
Paige (c) def. Charlotte

WWE Title
Daniel Bryan def. Seth Rollins (c)

Loser Leaves WWE - Street Fight
John Cena def. Brock Lesnar

Pre-show

NXT Tag Team Championship
Finn & Hideo Itami def. Vaudevillains(c)

NXT Championship
Kevin Owens def. Sami Zyan (c)

Main Show

Andre The Giant Battle Royal
Winner: Big Show

US Championship
Ryback Def. Rusev (c)

Cody Rhodes def. Goldust

Tag Team Championship: Table Match
The Ascension  def. The Dudley Boyz (c)

Mizdow def. Miz

Seth Rollins def. Randy Orton

Intercontinental Championship: Triple Threat  
Dean Ambrose def. BNB (c), Dolph Ziggler

The Undertaker def. Bray Wyatt

Sting def. HHH

Daniel Bryan def. John Cena

Divas Championship: LumberJill
Charlotte def. Nikki (c)

WWE World Heavyweight Championship
Brock (c) def. Roman Reigns

Seth Rollins cashes in MITB for WWE World Heavyweight Champion match
Rollins def. Brock (c)

Pre Show

Tyson Kidd and Cesaro vs The Lucha Dragons
Winner Tyson Kidd and Cesaro

NXT Battle Royal
Winner gets placed in the Andre The Giant memorial Battle Royal (Winner; A. Neville)

Miz TV with Rusev

Main Card-
Tag Team Title Match
The Dudley Boys vs The Accension vs The Uso's
Winner; The Accension

Dean Ambrose vs Sheamus
Winner; Dean Ambrose

Andre The Giant Memorial Battle Royal
Winner; A. Neville with Paul Heyman coming out and shaking his hand.

John Cena vs Rusev
Winner; Rusev

IC Title Match
Dolph Ziggler vs Ryback vs Bad News Barrett
Winner Bad News Barrett

Cody Rhodes vs Goldust
Winner Cody Rhodes

HHH vs Sting
Winner; Sting

WWE Heavyweight Title
Brock Lesnar vs Roman Reigns
Winner; Seth Rollins via cash in

Passing Of The Torch
Bray Wyatt vs The Undertaker
Winner; Bray Wyatt