World of Warcraft Death Knight DPS Rotation for the Unholy spec is based on magical spells.

The DPS Rotation is as follows:

Single target

PS,IT,BS,BS,SS,UB,DC.SS,SS,Rinse and repeat

Multiple targets

PS,IT,BS,BS,SS,SS,PEST,BB,UB.DC

Every 60 runic power raise you gargoyle.

PS=Plague Strike, I lead with this to get the blood plague on the target.

IT=Icy Touch, This is next to place the frost fever on the target reducing its movement speed.

BS=Blood Strike, Causes 60% weapon damage and x amount per disease.

SS= Scourge Strike, Does 60% weapon damage as shadow damage.

UB=Unholy Blight, All targets with in a 10 yard radius of the death knight take x amount of shadow damage last for 20 seconds.

DC=Death Coil,Fires a blast of unholy energy at the target causing shadow damage and healing the death knight some.

PEST=Pestilence, Causes shadow damage to the target and spreads disease to all targets in a 10 yard radius.

BB=Blood Boil,Causes all targets in a 30 yard radius to erupt in agony.

The World of Warcraft Death Knight Unholy is my personal favorite because of its magical spells and the ability to spread your disease to all targets and as i like to say pop them with Blood Boil, I find the AOE DPS from the Unholy tree  to be very high.