Adventure games like The Secret of Monkey Island and the King’s/Police/Space Quest series (all Sierra On-Line classics) used to be immensly popular. And still the gerne seems to be very much alive as many independent developers are still creating great adventure games, releasing them for free even.
Independent gamer has an article on the Top 20 adventure games of 2006, conveniently listing all of them on one page including a bit of info, download links and screenshots.
The random Gnomes’ random Lair has a complete list of nominees and winners of the 2006 AGS competition, including download links and -where applicable- reviews, official websites, interviews, etc.
Make sure to check these sites out if you’re into adventure gaming!