For close combat, I'd have to say, as a Guard/Tau/Chaos player, that my favorite CC unit is Kharn the Betrayer. He hits an Avatar of Khaine as easily as a Fire Warrior. Most of the time, he wounds on a 2+ as well, and ignores saves. With 7 attacks. At I6. That's about as insanely good in combat as you can ask for. He'll cut through your average Warboss, Hive Tyrant, Chaos Lord, Space Marine Captain, Heroic Senior Officer, XV8 Crisis Battlesuit Commander, Necron Lord, Inquisitor, Autarch, or even Archon one on one most of the time. Have him take on a unit, and he'll cut through probably (unless your dice are really bad) 1 less enemy than his number of attacks. For 165 points.