Free usually means not good. The 3D Downhill Skiing Game called ORF-Ski Challenge 06 is one of the exceptions.

Update:
Free Ski Challenge 2007 with English menus available now

This is the second season Austrian TV station ORF is offering a free downloadable 3D downhill skiing game. The 2006 version is highly enhanced, because of the huge success of the first release in 2004, where they clocked 700,000 downloads during the Winter season.

The game uses real 3D data of world cup downhill tracks like Groeden, Bormio, Wengen und Kitzbühel. If you register a username your time is listed in the central online ranking. You can be a virtual Herminator (Hermann Maier) with this game so to say.

The game is highly addictive, because it is fast to play, you want to be faster than your friends and you only use 4 keyboard keys to play. Instructions are only in German, but the game interface is visual and easy enough to figure it out quickly.
Download the free Skiing game here.
Works with most state-of-the-art Windows PC configurations.

Quick Tips:
Currently only Qualification is playable. Later in December racing days open, where winners actually can race of real prices.
Steering is done with cursor keys (left, right). Hold down the up cursor key to stay low. Only release when you have to make a hard turn. Hit and hold space key to keep low during jumps. That is it!