2002 XYZZY for Best Player Character
2002 XYZZY for Best Puzzles
2002 XYZZY for Best Story
2002 XYZZY for Best Game
Textfire Classic's Savoir-Faire is an old-school puzzle game set on a French estate in the 18th century, but using simulationist techniques to provide a complicated game world. My sources suggest it takes about 10 hours to play, or less if you make extensive use of hints; I have rated it a "Cruel" on Andrew Plotkin's scale of game fairness, because it is possible to make a critical mistake without even realizing it at the time. Save early and save often.
Savoir-Faire is downloadable from the IF Archive. The current version is 8. If you have an older version, I strongly recommend replacing it with the new one: old versions have some bugs that make some of the puzzles considerably harder, and one or two that crash the game outright. You can even try the game online, though if you decide you like it enough to play the whole thing you will probably want to install it on your own computer.
Liquid modelling: Because it describes everything that works in the game, just perusing the list might be a bit spoily for some puzzles. Mainly for the amusement of people who have finished the game or don't intend to play it, and have an interest in simulationism. Almost all of these liquid modelling effects are achieved by the Inform library extension WaterElement.h. It comes with instructions, which you may also peruse online.
Version History: Contains spoilers. But also some moderately funny things, I suppose.
Feelies: Feelies for this game are available from feelies.org; with the postage and PayPal fee they come out (in the US, at least) to a little over $5, which is what I charged for them on r*if when I first offered them. They include a letter from the Count, a booklet about linking, a diagram by Marie, and an authentication letter from me. Sort of. They contain some information about how the game world works and might be useful sources of hints, but are certainly not required to solve the puzzles.