1644 MST3K.

People who love MST3K also love to share MST3K with others. That’s part of how it survived so long. In the credits of the show they even encouraged people to keep circulating recordings of the shows. The first copy I ever received from someone else was my favorite episode The Final Sacrifice. Many years later, when they finally put the episode in a box set, I bought it, even though the copy I had was pretty high quality. I think MST3K The Movie is probably the best “episode” of them all in that it’s very easy to introduce someone to the series with. It’s also one of the best examples of the show, particularly Mike episodes, as far as how tight the comedy is. There are no slow parts. Manos, for example, has long stretches that are nearly unwatchable, in my opinion, because there’s nothing for the cast to work with. Part of the reason The Movie works so well is that the film they’re making fun of is actually considered a science fiction classic, rather than a flop. It’s actually a shame that they couldn’t use the material for Riftrax to make new episodes because much of the strength of that content comes from very similar things.
I’m a fan of the Mike years. I don’t hate Joel, but his comedy was kinder and more low key, which doesn’t resonate with me the way Mike’s does. Because of this I own very few Joel episodes. I can hardly name any of them in fact. Manos is the only one that springs to mind and I actually don’t like it. I do enjoy the shorts that Joel did and have a collection of them.
My favorite episodes, in no particular order, are: Final Sacrifice, The Movie, Space Mutiny, Hamlet, Overdrawn At The Memory Bank, Time Chasers, Final Justice, and Prince Of Space.
I’ve made a point of trying to buy as much official DVDs as I can, but they are just too expensive and hard to get in many cases, so I still watch some of the episodes on youtube. They are constantly being put up and taken down so it’s hard to know exactly what you can find at any given time, but there’s almost always an episode I’ve never seen on there still. I’ve never been able to see every episode, but maybe over time I will. XD
I know there must be people out there who’ve never seen the show. As a nerd it’s pretty hard not to have least heard of it in passing, but I know there are people who’ve never heard anything about it at all, and it’s great to be the person who shows them their first episode if they actually enjoy it. If they don’t… Not so much. I tried to show them to the Teen when she first came to live with us and she was not impressed. I think she might be more capable of enjoying the show now, but I would bet that she’d actually like the Riftrax of Twilight more than MST3K proper.