Best ending? Case closed
It's not exactly bumping, no 
I really didn't like After Story's OP, I believe it deserves better! It's kinda weird, has some weird time signature changes and stuff - and I'm usually really into those (like in the Little Busters OP for instance), but in this case it like changes into some weird 5/8 stuff - in my opinion it's kinda creepy :S
But the opening for Clannad, "Megumeru" is totally amazing, I can't even hum to it without crying 
I actually enjoyed After Story's op more than Clannad (I really like that part at the end), but both of them are great imo
EDIT: Actually, since I posted Glitter, here's my other fav Fairy Tail songs (that said, I love the whole soundtrack and anime)