I'll put it this way, Final Fantasy 7 is where I started hating my previously most loved game series, Final Fantasy 8 had me disgusted enough to melt the cd's. Final Fantasy 9 made me happy because there was a lot of fan service. Final Fantasy 10 made me break the DVD with a hammer and I stopped buying until 11 which I simultaneously loved and hated. As for Final Fantasy 12... it's another case of hammer though I haven't gotten angry enough at it to do that.
4 is the best, Kefka could kick Sephiroths a$$ and Rhydia is the only summoner I'll acknowledge.
P.S. "Ha take that b*t*h!" -Me to Aeries death scene.