Let's see... I didn't like FF4's plot, characters, or villains. (I would've liked the Dark Knight, but he wussed out and became a Paladin with useless powers.) Some of the music was fine, but that's not a good reason to play a game. It's better than FF8, but only by a certain margin.
Meanwhile... Chrono Trigger had a plot that kept unfolding and impressing me, again and again. The characters were all uniquely different and cool, some of them from different eras entirely. I loved the boss fights and the music selections. The villains, both major and minor, were done exceptionally well. Plus, it had time travel. Not hackneyed time travel, but GOOD time travel.
Play Chrono Trigger!