(edited by MobMama.5648)
Random Acts of Epic-ness: Champion Kol Skullsmasher
If this is the one I am thinking of where you fight these 3 hounds before you fight that boss guy I remember that was one of the more memorable events and its pretty cool.
This game when it has big challenging chain events like this one where people have to actually coordinate and try is where this game really shines and shows how unique and fun it can be. Too many events though are not this good and just are way too easy.