There's a free weekend and sale on right now for Tripwire Interactive's World War 2 shooter Red Orchestra 2. If you didn't try or pick up the game during the last free weekend and sale, now's another chance for you. To get in on the free weekend, boot Steam and look for the game in your library and start downloading.
If it's been awhile since you've last checked in or just haven't followed the game much to date, it was in rough shape at launch, partly due to poor performance. In the many months following, Tripwire finally brought the game up to par, and it now runs beautifully, and with a lot of other improvements and added content. To put it another way, it's well worth playing now.