First, I think 1999 was a very hard year to compete with because there was a lot of great feuds, and a lot of classic matches, so picking one out of the group is going to be completely hard to do. However, the Rock v. Mankind match at the Royal Rumble would be considered a great one.
Now the upside to this is while both men were already known, I strongly believe this match remade both of them for the Main Event spot. Mick Foley was already known as the guy who'd kill himself for ratings. And The Rock was unofficially the people's champion, even as a heel. However, when you truly break this match down.. should it be considered the MOTY when the most commonly used move in it, were chair shots? I'm torn but I'm going to say.. NO.
Now here are some examples I brought up.. (before)
1. No Mercy: Ladder Match: Edge & Christian v. The Hardy Boyz: If you want a gimmick match that steals the show and takes your breath away, turn your eyes from fat guys taking 2,000 chair shots to the face.. and rewitness the awe-inspiring Ladder match that MADE all four Superstars into what they are today.Without this ladder match, Jeff & Matt, Edge & Christian, none of them would be worth talking about and never would've got a second look. It was this ladder match that stole the show, and was (still is) talked about for years to come.
2. Wrestlemania XV: The Rock v. Steve Austin: How this match wasn't instantly put in the "can you top this?" I'll never know. This was their first Wrestlemania match-up together, and its one of their biggest talked about matches to date. I'm not instantly sure why, because I was still iffy on The Rock being as over and huge as Steve Austin, to match him evenly, however they went out and put on a great show. And I honestly feel this match alone could and should beat The Rock/Mankind - I Quit match.
3. Spring Stampede: W.C.W. Heavyweight Championship: Hulk Hogan v. Ric Flair v. Diamond Dallas Page v. Sting: (w/ Savage as special ref.) This was one of the very few matches during the 1999 era that made me love W.C.W. In fact, the Spring Stampede & Slamboree p.p.v.'s both left me wanting more of the same.With this specific match, you had Hulk Hogan still a heel, yet gaining more fan base than the 'face' Ric Flair, who was turning heel in the process. You then had the natural face in Sting, and the unknown never before World Champion in D.D.P. Throw Randy Savage as the special ref. into the mix, and you have an explosive Main Event.This was D.D.P.'s coming of age match, and I love remembering it.
4. Slamboree: Triple Threat Tag Team Championships: Rey Mysterio & Kidman v. Raven & Saturn v. Chris Benoit & Dean Malenko: When I think of Tag Team matches, and a great Tag Team division.. I think of this match.You had a perfect blend of speed, hardcore/power, and technical ability all mixed into one. Going in, The Four Horsemen (Benoit/Malenko) were feuding with Raven/Saturn, and Kidman/Mysterio had the Tag Championships fall into their lap as a result. The outcome.. quite possibly the greatest Tag Team contest I've ever seen.. EVER!
5. Nitro: Chris Benoit v. Bret Hart: After the tragedy of Owen's death, there was a lot of concern over whether Bret Hart would simply retire from the business, or continue wrestling. This match, whether he stayed or left, was a tribute to Owen.. and it gave us everything and more.Chris Benoit and Bret Hart are two of the greatest technical wrestlers today, and this match proved why.
6. Guilty As Charged: E.C.W. Heavyweight Championship: Shane Douglas v. Taz: This was a great match for both men, and one of the very first E.C.W. matches I ever witnessed. I felt that Douglas had a great match with Taz, and Taz showed me that E.C.W. wasn't all about violence and weapons.This was a tremendous match, and anyone who wants to see Taz at his best.. should definately watch this match.
7. E.C.W.: Rob Van Dam v. Jerry Lynn: Numerous encounters from 1999, and you notice I didn't pick a single one out of the group, why? Because any one of them can top the Rock/Mankind, I Quit match. When you wanna see a great mix of power, speed, technical style and an overall great blend to a match.. you pop in an R.V.D./Jerry Lynn match. Anyone, doesn't matter. And it all started in 1999.
Note-Worthy Mentions: Billy Gunn v. X-Pac KOTR Finals, Rey Mysterio v. Kidman at Spring Stampede, R.V.D. v. Taz from November to Remember, etc, etc, etc.
EDIT: I voted R.V.D. v. Jerry Lynn, because it was a perfect blend of styles. Their matches had everything, and it was amazing that even for their first match to have everything, each one their-after continued to add more. How anyone could ever get disappointed with an R.V.D./Jerry Lynn match, I'll never know.