Statistically? FF7 sold/selling - more, story-wise I prefer FF7 as there was more character development both on the protagonist and antagonist side. Both villains went mad so that was pretty weak story telling, however, Rufus was the perfect Lex Luthor to Midgar, politicians usually win the "war" so it was nice to see them dabble on that side of the fence. Terra was the far more interesting character, while I did like seeing Cloud's struggle, Terra being an Esper was pretty badass.
FF7 however, had far more likeable characters; Barrett, Nanaki, Cid, etc.