I'm a Cloud 9 fanboy...
...and I will happily admit it. However, because of this, I'm also enjoying Flyquest, since 3 of their players are former C9 players.
And they play each other on Sunday.
On paper, it looks like Cloud 9 would just steam roll Fly, because, statistically, every lane of C9's (save for the Jungle......Moon is awesome) is simply better than Fly's.
But as a team, their effectively on par with each other, but I think Fly edges out here due to Hai being a God tier shot caller, whereas C9 doesn't really have a designated shot caller (they all kind of take turns making calls).
In essence, I feel that this will be one hell of a game. Cloud 9 will be better skillfully, but Hai (and, partly, Lemonation) will be able to read them like a book. Champ select may have mind games left and right, and team fights will be long and drawn out.
I don't know who to root for, but it surely is a game I'm looking forward to, and I'm almost certain that this game will be studied hard by every other team in the LCS.