My absolute favorite Final Fantasy game is IV, as it was the first to really draw me in with its cast of colorful characters and a protagonist torn between his beliefs and his obligations.
However, I also love Final Fantasy IX, X (I love playing blitzball). I've always wanted to try my hand at XI, as I love the idea of the game, but I don't have the kind of money to spend on a subscription.
As for side-games, I enjoy Crisis Core, FF:Tactics/War of the Lions and FF:Tactics Advance/A2.
EDIT: And I cannot forget (though it did slip my mind) the awesome that is Dissidia.
However, I also love Final Fantasy IX, X (I love playing blitzball). I've always wanted to try my hand at XI, as I love the idea of the game, but I don't have the kind of money to spend on a subscription.
As for side-games, I enjoy Crisis Core, FF:Tactics/War of the Lions and FF:Tactics Advance/A2.
EDIT: And I cannot forget (though it did slip my mind) the awesome that is Dissidia.