My first time playing MYST was with
MYST: Masterpiece Edition on GOG.
I wanted to experience the original game and even though it's pretty old I still had a great time playing it and it's still one of my favourite games of all time!
RealMYST Masterpeice Edition is also really nice, and gives off a nice 2000's vibe, and being able to explore the island in 3D is really neat too. Personally, being able to use full 3D movement wasn't that big of a deal for me, but you may feel different about that. I prefer the directed composition of the original over full 3D movement. It is nice though that you can choose to use the point and click method over full 3D movement if you desire, which I would recommend.
I've also played through the
2021 version, and while the environments are really well done, the character models are... less then ideal, in my opinion. There is an option to play the original character FMV's instead of using the new 3D models which helps with most of the game, however the ending sequence will still use the 3D models which is very jarring.
So my recommendation then is: If you want the full original experience, play MYST: ME. If you prefer full 3D movement, go with RealMYST: ME. If you can't stand older graphics, go with MYST 2021. Regardless of which version you choose, I highly recommend writing down notes using a notepad and pen/pencil! You can use a text editor in a pinch, but for a more authentic 90s adventure game experience, using a real pen/pencil and paper is a must-have for note taking. Advice wise, I'd suggest not using guides if at all possible, and if you are really stuck, there are some non-spoiler
hint walkthroughs online that help nudge you in the right direction rather than outright telling you the solution. (Although, if you end up playing Riven, I would not blame you in the slightest for using a guide since that game is super hard compared to MYST lol). Take your time, read EVERYTHING, take notes and explore!
Hope you enjoy MYST! It's a once in a lifetime experience!