Booking WWE vs TNA PPV

Main Event - The Undertaker Vs Sting http://www.youtube.com/watch?v=VDkvyUqi4Fw If there was ever any doubt as to what match would headline the Invasion PPV then you clearly have no idea about the state of the wrestling industry and the biggest match never to have happened. The Undertaker Versus Sting has been suggested for I don't know how many Wrestlemania's and with the two organisations coming together for the first time it would be foolish for WWE to miss this once in a lifetime opportunity. If you were to throw these together at 'Mania with Sting battling The Streak it would be clear 'Taker was going over. However in this environment Sting has the chance to defeat The Dead Man and give TNA the advantage going forward, assuming this wouldn't be the blow off to the TNA/WWE feud. This would also give Sting the chance to finally work a WWE PPV and give him validation when he eventually makes it into the Hall of Fame. What matches would you book if you were in charge of the WWE/TNA Crossover PPV? Have your say below.