Havoc
Havocs are the Chaos Space Marines' equivalent of Devastators. Like their loyalist counterparts, these guys drag the heavy weapons into battle, laying out copious amounts of fire to support their brethren. Havocs can equip most of the goods that Devestators can, though you won't be seeing any plasma cannons or multi-meltas on these guys. Unlike loyalist marines, Havocs still have access to autocannons that can be lugged around by a single Marine, which they are more than happy to bring along with them. They also like to stick big ass bayonets on their guns, just in case the opportunity to stab something with an autocannon, heavy bolter or lascannon presents itself.
In the tabletop they are more flexible that their loyalist equivalents, due to their acces to marks and special weaponry, however they lack the chapter tactics from which all loyalist marines benefit one way or the other, and compete with more unique options for the CSM army. Namely oblits, forgefiends, rappier batteries, defilers, amongst others. They are however far cheaper than any of the contenders in their role, in both real money and game points.