I think Final Fantasy VII is the best Final Fantasy game ever and probably the best game ever.
By today's standards, the graphics are not that good; but back when the game came out they were truly ground breaking.
I've played most of the Final Fantasy games and the materia system is by far the best in the series. The mini-games in this are also the best mini-games in the series. It also has the sweetest villians in any game ever. The storyline is also probably the best in the series. The characters are also the most likable characters in the FF series. Probably everything about this game is the best in the series.
One of the things I liked about it was after you solved it, there's still tons of stuff to do so you could basically still be playing it for years after you bought it as I have been playing it since I bought it 5 years ago.
Overall Final Fantasy VII provides an engrossing storyline and excellent gameplay with lots of stuff to do which will keep you playing it for years to come.