There's a lot...
I. Several matches in the Shawn/Trips feud.
II. Any Elimination Chamber match that doesn't have extreme in it.
III. Edge vs. Taker Hell In A Cell.
IV. Hair vs. Hair match at Wrestlemania 23.
V. Shawn vs. Cena at Wrestlemania 23.
VI. Eddie vs. Lesnar at NWO for the title.
VII. Hogan vs. McMahon at Wrestlemania XIX.
VIII. Kurt vs. Taker at NWO for the title.
IX. Taker vs. Trips at X-Seven.
X. McMahon vs. McMahon at X-Seven.
XI. That fatal four-way WWE title match at 2000.
XII. The first Wrestlemania match between Rock and Austin.
XIII. The steel cage Summerslam match between Bret and Owen.
XIV. Submission match - Austin vs. Bret.
Not sure what constitutes as important WWE matches, so I tried to stick with Mania matches, and no, this isn't the full list. To be honest, off this list, not sure how many will be crossed off. I don't think I'll ever watch Hogan vs. McMahon because I have no interest in ever seeing this match. Don't have that much interest in watching an Elimination Chamber match to be honest. Maybe the ECW one screwed my interest in that. Most of the other matches I just haven't set out the time to watch.