Well... I can't really decide between those two either... So I'll tell you the pro's and con's of each one.
If you choose a sad ending, it will be good because, well... It seems Gerard has made a big mess... And sometimes things just don't always work out. So, a sad ending would seem realistic. Because, while I dont know exactly what kind of "sad" you mean, but if I were Frank, I dont think i could forgive Gee...
On the other hand. A happy ending, one full of forgivness and undieing love is less likely, but it's just that... It makes people happy. Just remember, if you choose happy, it wouldnt be easy to just up and forgive Gerard and make everything all happy again. If you do use a happy ending, make sure it is realistic.
I'm sure either was will be fantastic!
Author's response
Thank you for letting me know your opinions. I know what you mean about a happy ending being unrealalistic, but it does make people happy. Then again, I can`t see Frank being able to forgive him, so...AAGGHHH I cannot decide! Oh, well I`ll just have to. I`ll try to update in a day or two, thanks again
xoxodakota