As a child in the 1980's, I was really hooked by the gimmick matches because of the hype they created. I remember the build-up for King Kong Bundy v. Hulk Hogan in the steel cage (the old blue cage, not the chain link fence cage). I think the rules of the match and the 'escape" aspect made it very interesting to me.
In my teens, I saw my first Scaffold match from Smokey Mountain Wrestling. the concept of this was so crazy that I had to watch.
Later, things that kept me interested were Ladder Matches (Shawn v. Razor...awesome), Hell in the Cell, TLC, and Ironman matches!
My advice:
1. Do not try to "convert" anyone into a wrestling fan. If they like it and want you to help them find some cool old matches to watch, then fine, help them. If someone pressured me to watch NASCAR I would attempt to kill myself.
2. Start off with the basics. A simple 1 on 1, normal match. Make sure they know the basic makings of a match and the "rules."
3. Some types of matches that could make a mild wrestling fan become a loyal wrestling follower: Ladder Matches, Hell in the Cell, IronMan Matches, TLC, Tables match, Old Steel Cage Matches (escape only).
Some matches you may want to share.
1. Bret Hart v. Shawn Michaels (IronMan Match WM 12)
2. Shawn Michaels v. Razor Ramon (Ladder Match, WM 10 & Summerslam 95'
3. Hell in the Cell (Mankind v. Undertaker, king of the Ring 98') (HBK v. Undertaker, Bad Blood 1997)
4. TLC
E & C v. Hardys v. Dudleys (Summerslam 2000) and (WM 17)
CM Punk v. Jeff Hardy (Summerslam 2009)