Talk about 3D or stereoscopic movies, you will also be thinking about the player. Well, if you already have a 3D TV for example LG 3D Cinema then it will not be your concern anymore, although the TV can only play the SBS format.
One most famous 3D player is Stereoscopic Player from 3Dtv. It's a great player, you can tell about if from their trial software, support wide variety input and output 3D format. Another commercial player is Power DVD which also support wide variety input and output 3D format.
But if you choose not to buy one, either choose to turn your Media Player classic (MPC) to 3D player (only SBS format) or Try Bino3D which is a free stereoscopic player, otherwise try them both because all of them are free.