Sorry to hear your friends spoiled it for you Slayn. :(
I wasn't really happy with the story but I did love FFXIII-2's default ending, the hidden ending and DLC Requiem of the Goddess ending didn't leave a good taste in my mouth though. :/
Square in the last interview I seen seemed very clear they will only have one ending because they want to end the game in a happy manner, as FFXIII-2's ending was far too sad they said. I personally don't like happy endings but it might be worth it still. xD