If you're chasing a little more expressiveness in your chord progressions why not try an e minor 7th. It's a great sounding and easy chord to learn. It shows up often in everything from jazz to power ballads to pop, rock and blues. Try substituting it anywhere you'd normally play an e minor chord.
Looking at the piano keyboard you'll notice that this is an e minor chord with the 7th note added. The guitar chord is a less linear, but all the notes are there. If you check out the notes given at the nut you'll see there's a few extra E-notes, which is the sort of thing that happens a lot with guitar chords. Notes are often doubled up. The guitar version shown is in the open position, hence all the open notes. It can be played as a barre chord also, but that's for a different lesson. Piano players practice this chord using one hand only. You could also try coming up with two hand configurations and see how you can move between this chord and other compatible chords.
If you can't read traditional music score this is also a great place to start. You can see on the music staff that all four notes land on the bottom four lines of the staff - that's E, G, B, D. So, you can learn how to recognise this e minor 7 chord and learn the names of some of the lines on the traditional notation.