Statistically, the PS4 has outsold the Xbox One by nearly double; There have been 23.3 million PS4s sold, compared to 12.8 million Xbox Ones. However, this does not necessarily mean the PS4 is the better system for you. It really depends on what you look for in gaming. The Xbox One has games made only for their systems, such as Halo 5. It's the only console with Sling TV and EA Access and it also has DVR Capabilities. On the other hand, Playstation 4 has faster and better graphics, in general, and has a faster bandwidth. 
Perhaps the bigger advantage of the Xbox One is the price. Seeing sales were not doing too well, Microsoft decided to drop its price on the console. The company hopes this will boost sales. . If you are undecided which console to choose, some stores allow you test out both. This will give you a better idea of which is better for you.