I really like complex chords, even varied voicings can make a chord sound completely different. I am a sucker for jazzy, really complex chords, I think hectic chords can sound really impressive, especially if fingerpicked or arpeggiated somehow. I also find odd time signitures very cool, same with modulation within a song.But at the end of the day, tis probably not right to set out to impree people, just have fun and sound good.