Hmmm... For me, I would build a Death Knight like this:
Preset: Knight
Race: Any (but Human or especially Undead thematically)
Abilities: Warfare, Necromancer, Telekinesis
Skills: Rage, Vampiric Touch, Blood Sucker
Talent: Morning Person (later, Comeback Kid if not incompatible)
Playstyle: Throw yourself into the fray mercilessly, cutting down your foes. You do not fear Death, you are death: When killed, have an ally resurrect you, taking you back to full strength instantly thanks to Morning Person.