Most of the time I use a variation of
wow power level for my DPS spec. This is the current variation I use, although I tinker with it fairly often to see what I like or dislike. I prefer Vampiric Blood to Will of the Necropolis, for example, even though both are more defensive than offensive abilities, as I prefer abilities I can choose to make use of over ones that go off by themselves. This build relies in great part on the synergy between Bloody Vengeance, Blood Gorged, Sudden Doom, Might of Mograine and Hysteria.
Blood Gorged increases your armor penetration by
wow power level as well as increasing all physical damage when you're above wow power level health. Meanwhile, the critical hits you're using to stack Bloody Vengeance hit harder thanks to Might of wow power level, and you're almost certainly using Heart Strike to wow power level Sudden Doom Death Coils, while benefit from your Morbidity over in unholy.
Also, with Improved Death Strike, you not only do more damage 30% more you also have an extra wow power level chance to crit, making it easier to stack up
wow power level. And of course you can always throw Hysteria on yourself for even more physical damage.