It's mainly just the easiest "vanilla" answer.
There's a million different factors between cameras, the one that'll be the best depends on what you need/want.
For example, if you like Mirrorless, but also want full frame, your options are either Sony, or Lei- scratch that, your only option is Sony.
If APSC if fine for you, and you want simpler more intuitive controls and don't mind a difference in technology, Fuji edges out Sony (because lets face it they focus more on doing MORE AWESOME STUFF with their cameras than they do making them fun to use).
etc etc
There's no real "one answer", really.