Oh, definitely disagree. Final Fantasy VII was my first exposure to the franchise, and while relatively fun, it ranks pretty low in terms of my favoured RPG's due to, in my opinion, a storyline focuses much too heavily on being epic and far too little on characterisation.
I think I'd say XIII is my favourite, closely followed by VIII. VIII had one of the best settings of a videogame I've come across in a long time, and some fun characters to boot - though, even so it suffered from too little characterisation.
XIII focussed on characterisation almost to its detriment, and for me, that's just fine. Yes, it's initial character designs weren't as brilliant as those of most Final Fantasy's, but as I value development over initial concept... yeah.