There's no particular scale that's preferable to anything really. Western music will use major scales, minor scales and modes. All depends on what sort of feeling you wish to evoke in your track.
Best thing to do is just experiment with scales and modes so you get to know their diatonic chords and what sort of feel you can put over with them.
Pentatonics are just five notes, the major and minor pentatonics when playing in either a major or minor key get used a lot because of their intervals, you can pretty much play the major or minor pentatonic over whichever scale you are using and whichever chord progression from the scale and it will sound right 99% of the time.
There's obviously a lot more than that to it, and sometimes people will play modes over certain chords too.