I'm going to tick off alot of people saying this, but I reckon that Crisis Core is the worst. The horrible cheesy rock music, a predictable battle system, Zack was transformed into a normal man into a stereotypical shonen anime hero, and Genesis and Angeal were so annoying. And they turned Aeris into a girl who was frighted of the sky. Come on, that's just mean, Aeris wasn never a feeble girl so why transform her into one ? Plus everything in Final Fantasy VII is now because of Zack. Seventh Heaven. Aeris's pink ribbon etc. Crisis Core made Final Fantasy VII into " All about Zack ". 
Also changing Cloud's Buster Sword into a special sword that was special to somebody who didn't originally exist in the FF7 universe till this game was made. Piss off, the sword belongs to Cloud. It's his special sword that made him famous within the FF world. Not some wannabe Rinoa angel.
				
			
Also changing Cloud's Buster Sword into a special sword that was special to somebody who didn't originally exist in the FF7 universe till this game was made. Piss off, the sword belongs to Cloud. It's his special sword that made him famous within the FF world. Not some wannabe Rinoa angel.

...XII was one of my favorites...yeah i guess you could disagree with the battle system being that you could set up your gambits to virtually control everything (like beating the last boss without touching your controller!) but you do have the option of controlling this...i preferred to have gambits for the more annoying issues like status effects or attacking certain enemies...this way i could still have a good amount of control over what was happening...but the option of everything being automated works well with power leveling easily...the story was a more adult or serious one...focusing around a corrupt "government" was a nice change from the typical "theres this really bad guy whos going to destroy everything!" kind of thing 