As a new feature on Steam it is now possible to recommend a game to your friends. Sadly, you can't see all recommendations for a game. Anyway, it is possible to see all recommendations made by a single user by looking at the Recommended tab under his games (hopefully, they'll add a link on one's profile soon).
Anyway, I've been recommending a few games so far, though mostly games I've already discussed here. You can see them all HERE. The link has also been added to the right hand side.