One of the main reasons, I loved playing against the Berserker's, was because they got you into the game. They made you pretty much sit and pay attention. Even though you have beaten the game more then one, they continued to prove some kind of challenge and some sort of threat.
It was always an Adrenalin rush whenever one of them came running at you from the side. Trapping you in a corner? Anyone else have that moment where your partner was down, right beside the beast. So you ran right up to it, missing it's long arms by an inch to revive your downed teammate?
Good times, good times.