#1 The Undertaker vs Kurt Angle: WrestleMania 22 - World Heavyweight Championship
When Kurt Angle defected from Raw to Smackdown in Janaury of 2006 to win the World Heavyweight Championship in a Battle Royal, it seemed like there was only a limited number of challengers for "The Olympic Gold Medalist" to defend his newly won title against, and The Undertaker was at the top of that short list.
Prior to 2006, The Undertaker had not participated in what many call a "WrestleMania classic", even though he had a great match with Triple H at WrestleMania X-Seven and another great match with Ric Flair the following year at WrestleMania X8. However, a showdown with The Olympic Hero would have removed all doubt whether of not The Undertaker had a classic at The Showcase of the Immortals or not.
For instance, the chesmistry Angle and The Deadman had is undeniable. Both men had two matches rated 4.5 stars just on Smackdown (September 4th, 2003 and March 3rd, 2006 respectively). In addition, their No Way Out 2006 classic is regarded by many as the greatest wrestling match of 2006.
If you placed the exact match from No Way Out 2006 into the main event of WrestleMania 22 with anouter ten minutes added, there would be two different scenes:
Scene 1: The Undertaker and Kurt Angle have a five-star WrestleMania main event.
Scene Two: The Undertaker adds Kurt Angle as victim number fourteen on The Streak.