I'm gonna have to go with XIII-2 on this one.

X-2 Pros - You had a lot of choices on how you did things. You could explore every area and get different outcomes due to certain things. The job system, battle system, and accessories made this game the best. I've beat X-2 over 10 times.

X-2 Cons - The story is based around three women and I can't get over the fact how cheesey it is. It was made for girls. Another thing is in order to get everything in the game you have to play it three or four times.

XIII-2 Pros - Nothing is missable. If you count the monsters you got over 100 playable characters. You can equip up to four accessories at a time. The game is super easy to play. The story line is also my favorite in all the series.

XIII-2 Cons - It takes too long to do everything. As a matter of fact to do all side quests you have to do everything besides open all chests. The DLC weapons are not all that great and even the DLC characters are for end game (bar lightning (COM) and Sazh (Syn).