I think I've enjoyed all the intros to all the FF games I have played. I guess I'll list them out to make this post a little bit longer.

FFVII- My first FF. It was amazing how the game shifted from FMV to actual gameplay.

DoC- Didn't really care for the game, but the opening was good. Like all openings, this one really set up what was going to happen in the story (I guess that's what the function of the opening is, huh?)

Crisis Core- Very action-packed and it showed the players exactly what kind of character Zack would be.

FFVIII- Even though this isn't my favorite FF, I will say that this probably has one of the best openings. Very cool, especially for 1999.

FFIX- This one was good. I liked how you played the game a little before the actual title showed up on screen.

FFX- I must say that when I saw this opening scene, it reminded me of a rock video. Very action-packed scenes in this one.

FF X-2- An alright opening, albeit a tad confusing until you figure out what the heck just happened.

FF XII- GREAT OPENING! My God. This was epic. It goes from Ashe and Rasler's wedding to total chaos of war. This was a long one, too. Got to sit back and watch the action.

FF III- Yeah, I went out of order. Ha, sue me. Anyway, I like the FMV that plays before you even start the game. It looks really good, especially on the DS

As for my favorite, I say it's a three-way tie between Crisis Core, FF VIII, and FFXII. They are all good, these are just the ones that I think do it a little better.