You can get a free copy of Knizia's board game Ingenious for the PC today at GiveawayoftheDay.com . It sells for $18 on Amazon.
It needs to fetch an activation key from the site during setup, but otherwise doesn't appear to have any other catch. I didn't see any spyware or have to provide my email address to receive spam. You have to download, install, and start the game today. And if you need to reinstall it at some later time you're out of luck. If you buy it on Amazon, it can be reinstalled at any time and comes with support, too.
It's a well-done version of the game, although the cheering spectators sound effect gets old fast.
And it's a good way to try out the board game.