What are some good, current adventure games for computers?

First of all, if you want to replay Myst or its derivatives, you certainly can on Win7. Head over to http://www.gog.com and see what they have on offer.  The pricing is reasonable, and they have a very good variety of games. http://www.gog.com/en/catalogue#adventure/ In there is Myst, Real Myst, probably Riven, and a lot of games from a similar background. If you're looking for something more akin to Monkey Island - a point and click adventure game with a story, dialogue, and such, there are a fair number of modern games in this style. Steam runs on Windows, and even if you've only got a Mac, you get about 10% of the PC game selection available to you. http://store.steampowered.com/ Look through the "Adventure" and "Casual" game sections.  The adventure section on Steam will include a lot of action oriented games, but there are demos of most things, and there are sure to be things you may enjoy. A good place to start would be Precipice of Darkness: http://store.steampowered.com/sub/7135/ Secret of Monkey Island - the original game, updated: http://store.steampowered.com/app/32360/ The Longest Journey - A modern adventure game with some action: http://store.steampowered.com/app/6310/ Fable 3 - more action in this game, and the story isn't great, and there isn't anything resembling a puzzle in the whole game.  But it's an immersive world where you can make your own story (well, sort of!): http://store.steampowered.com/app/105400/

Anything by Telltale will suit you well. They make episodic adventure games for PC, Mac, and iOS. Their franchises include Sam & Max, Monkey Island, Back to the Future, and more. The games are broken up into episodes and seasons like a television show. When a season is going, you can expect a new episode every month or so.

You may want to try out Dreamfall: Chapters, which just  came out recently on Steam.  It's a continuation of the Longest Journey series (which you should play the past installments of, even if they are older.) Other than that, as others have said, anything by Telltale Games is very popular right now in the adventure category.