Fcuk!!!!! Why this? Why in this round do my two favorite games in the competition(and really basically two of my favorite games period ) have to go up against each other?
In terms of side content, I'd probably go with Suikoden II on this. You've got the whole 108 stars of destiny and multiple associated endings (and in this case both getting the stars and the alternate endings add much more value than in the first game. I've also replayed this game so many times I think it probably beats FFVII in replay value (especially with the different endings), although I love to replay both games. The cooking mini-games is great too. Investigations of the characters is kind of nice. Optional recruitable characters even beyond the 108 stars. FFVII is no slouch either though. The whole Wutai quest, two optional characters that are nonetheless well developed and have their own unique dialogue throughout the game. For condor. All the Gold Saucer stuff, which is quite substantial. Chocobo breeding (ok, that's kind of awful but the rewards are huge). Gelnika, Ancient Forest, the Weapons. Honestly, I'm not even sure which game wins onside content,but I'll give the slight edge to Suikoden II if only because the best ending (which is technically optional) was probably about my favorite game ending of all time.
That said, I just spent all this time explaining why Suikoden has the edge in side content,but I'm going to have to give the overall win to FFVII. Why? Because I think FFVII is the clear leader in gameplay. Don't get me wrong, I truly love the game at of Suikoden II. I don't think it could have so much replay value if I didn't. Still the basic battle system is really a pretty simple straightforward turn-based system. Nothing wrong with that, but,lack of character differentiation notwithstanding, the materia system is probably my favorite gameplay system in FF games. I just love all the different combinations of things you can do with it. Suikoden II also has the second best army battles in the series (second only to the real time battles of Suikoden V), but that isn't enough to makeup the difference,not even with Suikoden taking the side content category. Ultimately, the win goes to FFVII for me.