I'll have to go with United, hopefully as scandalously and controversially as possible. Arbeloa, Pepe and Xabi get red cards, Young 'earns' 2 penalties (Rooney misses both), Di Maria gets cramp after 20 minutes, Giggs and Ramos score own goals, Benzema gets a goal disallowed in the 90:th minute of the return leg and United win on penalties (Ramos misses) with Ronaldo still waiting to hit his. John Terry then proceeds by joining the celebration in a United shirt, along with Giggs (ex-?)wife.
+ 2 Man U players get red cards from Di Maria/CR/Pepe diving. And then another gets one for breaking Pepe's leg. And then Real seemingly score the winning penalty in the 7th minute of added time from a dive from Di Maria. And then Man U equalize in the 8th minute of added time through a penalty from a dive by Ashley Young. Then someone on the Man U team pulls a Suarez in the 125th minute, and Ronaldo misses the resulting penalty, causing a shootout, which Man U wins.
And then Mourinho whines about a worldwide conspiracy against him to top it all off.
Basically, I'm hoping it turns out something like this:
Match 1:
2-2
15': Ronaldo (p)
20': Ronaldo (p)
89': Ronaldo (OG)
90+5': Van Persie
Match 2:
2-2
15': Ronaldo (p)
89': Van Persie (p)
90+7': Ronaldo (p)
90+8': Van Persie (p)
91': Rooney gets sent off from a dive by Pepe
95': Vidic gets a red card for a career-ending challenge on Pepe.
104': Arbeloa makes a red card worthy challenge, nothing happens.
105': Arbeloa gets a red card due to a dive by Ashley Young
105+1': Ferdinand gets a red card from a dive by Di Maria
115': Di Maria gets sent off for diving
120+4': Alonso finally gets a red card after a million fouls
120+5': Ashley Young pulls a Suarez, Ronaldo misses penalty
Man U win 5-4 in penalty shootout (after going down at some point)
All the penalty goals being from dives by Pepe/Ronaldo/Di Maria and Ashley Young respectively.