I personally feel that Lore of Shadow is THE best lore in the rulebook. Str 10 units, and debuffing stats is amazing, and Pit goes without saying. The pendulum is nice in the right situation also.
I will say though, (and i know this isnt the intention of the OP) anything that makes skellies better, makes ghouls EVEN better. Just saying
Anyway, with regards to our other core:
Skellies can work, but need a little more support to kill stuff. The ability to take Banner of Hellfire is FANTASTIC, as gets those flaming attacks in the army (and magical to boot

bye bye forest spirits!).
As i said, the best support lore at our disposal is Shadow. Hands Down. Even without mindrazor debuffing a units WS and then Helming them, or killing their Toughnes so its easier to wound, or killing their strength so that you can grind longer.
Dont disregard parry either, can make all the difference vs high strength.
Zombies do just suck though. I know that sounds very over opinionated and negative...but...theyre just...SO awful...SO awful.
They die in droves and require so much support to be just about on par with ghouls/skellies that its just not worth it. Half the amount of skellies will do better than the equivalent points in zombies. I dont even raise them any more.
Sorry, as i said it seems very negative of me to say that, but ive written lots of lists trying to make them work and i just cant get them to work effecitvely.
I will say that i am a competetive player to my core, so as much as the hobby beckons i think my lists writing will always be marred by that.