I have barely played FF7. I spent a few hours at a gaming store, and played through the first area. First, it was boring, then it wanted another disc. At this time, the PSOne was so unbelievably hyped here, I presumed it was just another crappy game that Sony had decided should sell well. I've never played it again.
A few months later, however, I began playing the second and third parts of the series, I think they're called FF4 (the one with Cecil) and FF6 (the one with Kefka) in English. I love both of these games, even though my love of action severely restricts my ability to play them.
FF4 is clearly an earlier game with regards to mechanics etc, and has a few balancing issues, but it's still good. The storyline is very linear... I think it was one of the first games to have such a linear storyline. The translation can be a pain sometimes, but overall it's not too bad. The storyline, however, actually managed to interest me, which is something only Chrono Trigger (which is a game you really must play, I cannot emphasize that more) had managed to previously do in a game. The art style was appropriate, and the relationships between the characters remained clear despite the dodgy translation. Most of all though, the game is fun... it's not the standard affair where all the characters have a set purpose in both the storyline and combat, characters can just be plain crap. (Or at one point one character becomes extremely powerful, and you can destroy all the monsters, which you have grown to hate, easily.) It's unpredictable, original and a breath of fresh air.
FF6, although I still haven't finished it, is also fun. My main gripe is the random battles... they can really be a bitch a lot of the time. The storyline, however, is well formed and the translation has really had a step up. Although the game contains more character cliches than the previous title, it still retains the air of suprise and suspense throughout most of it.
Neither of these games are what I'd call simplistic, although I have limited experience in the genre. Games like Skies and Chrono Trigger are if anything simpler than these games, which can often seem a little unstable a lot of the time. They both contain some excellent puzzles and they generally require you to use your head more than just buy/sell/level up. I'd highly recommend both of them.