FF VIII redefined Final Fantasy, the gameplay mechanics of VIII, are the best ever seen in the series, as was the GF's (which I call any summon from FF's after VIII) Eden (greatest GF to ever exist in a FF game) Bahamut, Leviathan, Doomtrain, etc... The limit breaks were (and still are) amazing, especially Squall's and Zell's. FF VIII just offered hours and hours of fun, that kept players on their toes. It also contains one of the hardest bosses in the series, Ultimecia. The way VIII was structured was perfect, and I have yet to see a FF game after it match it.
The best FF period, the first one that gave SE the reputation of offering the games with the best graphics and CGs, the first realistic characters in the series, the best FF couple in Squall and Rinoa, the first to not made use of swap pallette monsters and 99% of them being unique in Design, the best Final Battle, the best enemies (The hardest malboro to date), the best GF (Diablo and Eden for the Win) and the best ability system in the Junction System.
i had a gamesave for ff 8 just before the final boss and my GF saved over it accidently,i am replaying it on the vita and it is seriously the best way to play it, short of an hd remake.
Its simply an amazing game.