When I was very young, my parents both played the second game in the series - Riven. I grew up on Riven, and I enjoyed games 3 and 4 when they arrived. I also enjoyed playing the original Myst on the DS (found a game-breaking bug) and all was happy. And then I heard about Uru and 5. Both were major deviations from the series, with most of the old characters gone. One was set in the present time, and the graphics, so I've heard, were terrible. The series as a whole had a brilliant premise, one that drew in fans of all ages (pun intended) and challenged us to think. Most games now are first person shooters - there is little to no strategy, and most are bleak and depressing.
The first Myst was, since I played it as an adult, less than stellar for me. I had become used to solving puzzles, and I am ashamed to admit that I used a walkthrough for most of the game. It didn't draw me in the same way that it did most fans of the series.
Riven: The Sequal to Myst was the game I have the fondest memories of. My family owns the strategy guide, which also had a unique premise. Half of it was the Stranger's log, and the other half was a more typical guide. I am not ashamed to admit that I read this guide over and over again. I didn't really care about the help, and my parents both had notebooks filled with details and drawings to help them out.I would wander the Islands over and over again, meeting the people (those that I could) and typically enjoying myself. As an adult who has studied geology, I realize now just how flawed Gehn's work was. He must have completely forgotten to take plate tectonics into consideration.
Myst 3 was also one of my favorites. I never did collect all of Saavedro's pages, but Exile was one game where I seldom used a walkthrough. Since the game was designed as a test, it was easier to navigate than Riven. Fun fact - Wormtongue from the Lord of the Rings is the one who played Saavedro.
Myst 4 was my final game, played well into my teens. Spire gave me great difficulty, and I loved the mangrees and Serenia. Playing this game before the original, I have a deeper appreciation for Achenar, and a greater loathing of Sirrus.
Over all, I suggest this game series for anyone searching for a challenge. I promise that you won't regret it.