I vote for AVALANCHE!!!!

Reasons behind my decision are as follows:

(SPOILER)
In BC, they are secretly funded by Rufus ShinRa.


(SPOILER)They are also as strong as SOLDIER 1st Class in BC.

Mr. T is in it lol

The Forest Owls were serious losers!

And The Returners.......well I don't know much about them

As for Wild Rose, I didn't pay a lot of information to FF2 so I've never heard of them xD