minor

Compare this one to the major chord with the 3 up on the 4th fret and you'll see why the 3 is so important.

The root on the top, this a good sounding voicing and an easy moveable shape to grab.

These chords really need all three notes but this is another easy moveable shape to grab and even without the tonic is one that you'll use a lot.

With the root in the bass and the 3rd on top this is your standard minor voicing and another moveable shape.