Best one with a berserker was my Assault shot him with his alloy cannon, the berserker charged the source of the shot and set off the assault's reaction fire for enemy walking within 4 squares and got another go straight in the face. No more berserker.
My favourite one was a muton berserker charging through my group. He charged at one person, someone else would shoot him. Then he would charge at who shot him. It repeated like this a couple of more times, he never attack anyone, just charge at them, then charge at someone else. Whittled down his health then my arc throwing rookie charged in for the stun