It is very difficult for me to answer this question, because I love everything in this game! There are so many wonderful things in Final Fantasy XII, that I honestly can't pinpoint an absolute favorite moment.

Some of my favorite moments are anything that features Fran. (I have a Fran fetish!)

Other special moments for me include getting multiple Grand Helms, suits of Grand Armor, Ribbons, Lordly Robes, and Brave Suits. Basically, anytime I obtain any of the "Ultimate Equipment" it is a special moment for me. The first time I got all my characters leveled up to 99. Achieving a 999 chain on Abysteel in Henne Mines was pretty cool. I suppose two of the most memorable and special moments was when I finally defeated Zodiark and Yiazmat. (Zodiark, used to kick my tail and now I can beat him in around a minutes time! Yiazmat on the other hand, is still rather tough for me even when applying the 50 min strategy.) Lastly obtaining the Wyrmhero Blade. (Even though it's pretty much worthless at that point in the game.)

I could go on and on, but those are some of my most treasured moments.

(I'm yet to obtain a Zodiac Spear in the Henne mines, even after weeks of non stop trying. If I can ever luck up and do that, then I'm sure that will be my most treasured moment. Lol! Other than that there are only three things left for me to do: Obtain the Danjuro, get the 99 Red Chocobo to appear, and do the 122333 challenge.)