First I'll get to the goods and the bads.

Goods:
-Good story.
-Nice balance in the difficulty settings; you can make the game easy or hard enough for you.
-Great mechanics and battle system.
-Charming visuals if you're into cell-shading.
-Replayability and post-game are quite extensive.
-Hours of gameplay, tons of them.
-Incredible soundtrack.
Bads:
-Sometimes it's easy to break; making you reload saves that might be far away.
-Not all the mechanics and items are as easy to pick up as someone might expect.
-Quite a bad port, textures aren't great and framerate is capped, problems with V-Sync. Granted, it's an old game, but still not a good port.
-Maybe a bit on the lenghty side without guides.

So, now, with my opinions.

This is the game of my childhood, so I'm extremely biased. I loved it, every single time I played it, and ended up completing it 15 times on the GameCube, 3 of them being 100% which is quite challenging. Characters are great, they are constantly evolving in what in my opinion is a great story line. The visuals were nice back in the day, although now a bit of an overhaul is absolutely needed (There are texture packs for the game if you so desire). The soundtrack is incredible, maybe a bit too synth-y, but absolutely a masterpiece. I ended up spending about 2k hours on the game on the gamecube alone and I'm absolutely going to spend at least 200 more now that I have it on Steam.
It's a classic. One of the best JRPG's that we've ever seen in my opinion.