bar chords are probably the easiest chords next to open ones. once you start getting into more complex voicings of chords like inverted chords and jazz chords... that shit will make you want to break your fingers just so they go in the proper fret. yeah, knowing basic chords and what goes well together is cool, but music theory itself is what opens up new doors. for instance, playing a diminished 2nd or a tritone by themselves sound gross. but implementing them in a chord will bring so much color into your playing. if you only rely on your ear to get you by, chromatics will never sound good to you. learn as many scales and modes as you can.