Riven: The Sequel to Myst
I know; worst name on Earth. The people at Cyan probably just wanted to call it Riven, but realized that it would be throwing away all the credibility that the name "Myst" had.
The reason for selecting it is that it shows exactly what an adventure game is. It has incredibly clever puzzles, that are so intricately woven into the world that they don't actually feel like puzzles. Except when they do of course, but even then, they're not puzzles so much as elaborate security systems devised by people for reasons that are very apparent.
The beauty of Riven is that it tells you all of this with very little "dialog". It never once breaks kayfabe. Your character never talks, is never seen by you. This isn't even like Half-Life, where you are a particular person (Gordon Freeman) and you can see yourself in mirrors. You can literally imagine yourself there, and just about nothing is ever done that breaks the illusion.
Another thing in Riven's favor is how it gives you information. This game will exercise your Comprehension like no other. You have to learn numbers in the D'ni language. There is one device in the world (suitably in a classroom) that teaches you numbers, but it doesn't teach you it by showing an arabic numeral followed by a D'ni numeral (that would break kayfabe). It teaches you in a more abstract way that requires a certain degree of comprehension for the player to pick up on it. Furthermore, it doesn't teach you everything about D'ni numbers either; you learn 90% of what you need to solve a puzzle, and are expected to deduce the rest. The deduction requires some guess-and-check, but the answer should be fairly obvious for those with enough comprehension, or for those who take enough time to look at the number symbols. It really is a well-crafted puzzle, especially for someone like myself who actually knows a lot about number theory (numbers in non-base-10, etc).
The entire game delivers information visually and auditorially. It also, in true Myst-game fashion, delivers information through a number of journals. However, in most cases, these journals are far enough into the game to where you have already picked up the subtle clues to much of this already in the world that you have seen so far. This is part of the game's genius.
Another piece of genius that should be noted in an academic setting is that the game revolves around solving 2 puzzles. These are world-spanning puzzles that require accumulating vast quantities of information to even find out about them, let alone solve them. The nature of these puzzles should be discussed at length,
Now, the game does have some downsides, despite its genius. The game has one puzzle that is patently unfair. It is a basic Negative Knowledge Pathology. One of the two world-puzzles is broken in that entering the solution to the puzzle is basically impossible. Imagine having a puzzle where the solution is a 5-digit code. Simple enough: find the 5 digits and enter them in the right order, and the door opens. Now imagine that the keypad that you enter them into is not a regular 10-digit keypad, but in fact has 20 keys, where many of the keys are repeats. So there may be 4 copys of the number 5, etc. Except that the 5-digit code does not give you a way to differentiate between number copies, yet it requires that you hit a certain number 5 or a certain number 4 to enter the code correctly. That's what the pathology in this game is; you can absolutely know the code, the digits and the order of entry, but you may not know how to enter them correctly. And the number of viable entries is so vast that sitting there and entering them all would be very boring and utterly destroy the illusion of the game.
The take-home object lesson for this game is puzzle design and worldcraft. And, of course, how easy it is to create a negative knowledge pathology just because someone on your art staff though it would be funny to have a number of symbols look very similar to one another (you'd understand if you knew the puzzle).