I'll admit, the first time I played Myst I was a young child who wasn't nearly smart enough to figure out the games many puzzles on my own. My parents, seeing this, quickly bought me a guide and I had the game beat in an afternoon.
Flash ahead 15 years, and I'm sitting in my college dorm room helping my friend with a class assignment. It was a technology and writing class, and he needed to complete this game and write a paper about it. I vaguely remembered some of the environments and puzzles, but of course I didn't remember how to complete them. So, we spent several days figuring out without any kind of guides the solutions to the puzzles. It was a great bonding experience between us, and we both felt like we accomplished something afterward.
This game is a legend in gaming history. Its puzzles are legendary, its locales are well-known, the characters (though they play a minor role) are still strangely memorable. True, the graphics look a bit dated now, but they still evoke a bizarre sense of emptiness that few other games have done. As your explore the world, you ask yourself, "Why is this place so barren now? What happened to the people that used to be here?" The sounds effects also help the atmosphere in such a powerful way. They are never overbearing or overdone, and are often quite subtle.
The best part of this game is simply exploring. The environments are so creative and varied. Its truly unlike any other gaming experience you'll ever encounter, past or present.