FFI - pretty much everything after you get the airship. The freedom in the game combined with all the best loot and job upgrades always makes this portion of the game fly by as opposed to the long drag that is Elfland and finishing the southern continent in general.

FFII - I don't really have one, but I do really enjoy the Dreadnought sequence for the Star Wars reference.

FFIII - Probably the sequence with Aria, it starts with the revelation that your home is a floating continent, has some really eerie music and one of the most tragic deaths in the game all with some of the game's best music and the first actual character theme in the series.

FFIV - Either the whole final half of the top world starting with Mysidia and Cecil's quest to become a paladin all the way to the end of the Tower of Zot sequence. Has probably the most intriguing party configurations, some of the most memorable moments in the game, and the coolest dungeons. My second choice would be the entire final act where you finally go to the Moon, come back to fight the Giant of Babil and learn about Golbez's true heritage, and leads to the final dungeon and ending.

FFV - The entire second act on Galuf's world up until the world's merge. I really feel like it's the point where the plot picks up and you finally have access to most of the classes and a means to really get them leveled up quickly. The Dawn Warriors are cool, and you get highlights like Galuf's death, Battle on the Big Bridge, Forest of Moore, and ExDeath's Castle.

FFVI - Easily the toughest one for me, because I love this whole game,though I may give this to the second act as well starting with Terra's disappearance and ending at Kefka destroying the world. You get some super memorable sequences, good character moments, access to espers, and some of the coolest dungeons.

FFVII - Midgar, easily my favorite sequence. No sequence afterwards ever really grabbed my attention like that part.

FFVIII - Probably the whole Dollet sequence. It was cool seeing the changes from the demo, I loved the SeeD grading mechanics, and I feel you get one of the coolest sequences with the robot spider. For the most part, the entire first disc is my favorite part of FFVIII.

FFIX - Don't have a particular favorite but perhaps the entire opening up until the party finally reaches Lindblum and splits up. Some great sequence like the kidnapping, the Evil FOrest, the battle with the Black Waltzes, and Vivi learning he's a synthetic being. Nice stuff.

FFX - The opening sequence up until the end of Besaid. Lots of cool mysteries, the cast is still likable for me and the pacing is nice and never overstays it's welcome like the rest of the game.

I'll do the other half later.