A Centurion's weapon of choice is the laser rifle.
Laser rifles are larger weapons in both the Colonials and the Cylons arsenals, although they are more commonly used by Centurions.
The version used by the Cylons is wielded by Centurions and is capable of operating in all types of conditions, including cold (TOS: "The Gun on Ice Planet Zero, Part I") and damp (TOS: "The Young Lords") conditions.
The notable differences between this and the Colonial version is the circular muzzle, in addition to a small, jagged bayonet made from a clear material.
The Colonial versions of these rifles do not appear to be commonly used by Colonial Warriors, although they are kept aboard the Prison Barge.
The notable difference is the the large crystal at the muzzle-end of the rifle, in addition to a sequential light at the side of the weapon, apparently indicating power (TOS: "Baltar's Escape").