Valentines Day comes with all kinds of good tidings. If you havent already given The Witcher and The Witcher 2: Assassins of Kings a try I highly recommend that you do so this weekend. Both games will be available on Steam for free until Sunday at 1PM PT. During that time you can play both as long as you want and even pick them up for 80% off ($6 for both) during the weekend sale. So if you plan on playing the upcoming third and final installment, The Witcher 3: Wild Hunt, now is a good time to get caught up.
Source: The Witcher Free Weekend