Vikings by far. Their methods were known far and wide, and the managed to spread from Scandinavia(Now Sweden, Norway, and Denmark) all the way to Iceland. If you don't believe Vikings were more savage, look up some of the torture methods. Especially the Blood Eagle.
On top of this, some of them rushed into battle wearing bear pelts(Berserkers) and wolf pelts(Ulfhedinn Translates to Odin's Wolves). That's some savage stuff man.