Well, my list plays out a little bit differently because home video and cable movie channels weren't a factor in my childhood or adolescence. The only way to see a movie multiple times was to keep going back to the theater, or scour the tv listings to try and catch it whenever it aired. That's right, kids - in my day sometimes we had to set the alarm and get up at 3 AM just to see a movie a second time.
So with that level of effort involved, for a movie to make MY list it was obviously a pretty big deal.
I'll start with the obvious one:
1. Star Wars (1977)
I mean, duh. Ten or more viewings in the theater during the original release, and several re-release viewings after that. As soon as "home video" was no longer exclusive to millionaires it was one of my first video purchases, but I was out of my teens by then.
2. The Ωmega Man. (1971)
Damn right I used the symbol to spell the title properly because RESPECT.
I was not yet a teen when this was made but was too young to see it at the time. I discovered it on tv a few years later, and from that day forward I watched the shit out of it every chance I got. My well-documented love of downer apocalypse movies follows a straight line leading right back to The Omega Man.
3. Harold and Maude (also 1971)
Did not see this during its original release either (see above) but neither did nobody else. But then H&M became of the most popular "midnight movies" of the '70s (second only to Rocky Horror, pretty much). So it was possible to catch a screening of H&M pretty much any weekend of my teen years. Which I did, at every opportunity.
If there's any single movie that determined my worldview to this day, it's Harold and Maude. To know it is to know me. If you dare.