I personally like spears. It's fun to skewer my enemy's internal organs, although it doesn't work well through iron armor (bronze spear).
I'm guessing they are multigrasp, so you don't need a shield? Also, I'm guessing spears aren't one of those weapons that are good against everything?
Spears aren't multigrasp, but pikes are.
Stabbing attacks like spears (but not as much swords) can shatter bones, open arteries, and damage internal organs. They ignore natural armor (like scales) but only sometimes penetrate metal armor. They are good at disabling by stabbing extremities and severing arteries and nerves, and also good for destroying internal organs. Shots to the upper and lower bodies also have a fair chance of severing the spine. Stabs to relatively small creatures (including bogeymen!) can actually sever body parts.
Slashing attacks are best against small unarmored targets. They can sever arteries and nerves consistently and even cut off limbs. They are best at killing through bleed-outs and headshots, since slashing attacks don't hit internal organs often. They often glance off armor and cannot easily penetrate natural armor like a hydra's scales.
Crushing weapons are only effective at causing pain and headshots. Crushing attacks to the upper body can occasionally drive a rib through an organ, but this is uncommon. Crushing attacks are good at shattering bones in limbs to cause pain and disability or caving in heads for a kill. They rarely cause bleed-outs.