It has a snappy and convenient OS, fast installs...
games run well on it (no 70% 1080p justification)
the controller is great (the 3 consoles have good options, as far as controllers go, even if you have to buy the game pad pro for the wii u)
it just works as a gaming console, the features of the os are "just there" you don't need a tutorial to find your friends list!
etc.
not saying it's the best at everything, or that it has the most features, but it's certainly the best console available right now...