Currently I use a Chaos Lord and 2x5 Squads of Terminators. Usually at the 1500 points bracket.
The Lord has various load-outs, most recently I'm using him with Terminator Armour and Twin-Lightning Claws and a Mark of Khorne.
One unit is an Oversized Termicide with all combi-meltas and Two Chainfists.
The other Is a Mark of Slaneesh unit armed with combi-meltas and power weapons. The lord deploys and fights with these.
It's not competitive at all, but I take them because I love the Idea of a Chaos lord (King of Badassery) and a retinue of madmen in terminator armour (his Squires of Ass-Kickery) chopping stuff up. Hitting with so many power-weapon attacks really does munch through opposition units. However at the moment they tactically suffer, as they either deepstrike (and are usually charged) or footslog and get shot to death. I'm currently working a list at 1500pts to bring a Land-Raider, and it's been so difficult to play with that I've even had the lord get one-shotted by a Las Cannon.
Another solid reason to use them means that I basically play with the idea in my head I don't have any Daemon Princes. The one I do field is almost 90% bluff to get shot at to allow Rhino's containing Zerkers and Plagues to move up to positions. I almost play every game thinking "I'm 175 or so points down, how do I use tactics to win this." It really has helped develop my game and it makes me smile when the Daemon prince actually does something.
"Ambition is the biggest killer of Momentum"
Starting afresh with my Chaos Space Marines.
Project Log Link (Placeholder) -
Project Rebuild, Reboot, Recycle:
Stripping, rebuilding and remaking my Guard army.