A paladin challenged me to a duel at lv4 when we both leveled in a group, because he saw I had no damage and he had a new glowy weapon. I ghoul's touched him, mostly out of desperation expecting to lose, and found out I auto-hit auto-crit! He went down like a ton of holy bricks.
I really like Ghoul Touch too.
He was none too happy, but now my favorite past time is going invisible, running back and ghoul's touching the enemy healers and casters with crappy fort saves. Then I can beat them down with my mace and dagger lol. I'm only 7 so far, but at lv10 I have a cool looking Body Feeder sword I can start to swap out to for some life tapping. Offhand will be a body feeder of maiming dagger which is pretty brutal on auto crit, but it's ugly. I may try to trade it for another sword of the same curved style.
Look out for "Burst" weapons. Especially Holy Burst for criticals yumminess
I need to look through the spells for an anti-tank spell though. All my best necromancy so far is fortitude saves, and enemies of tankish varieties on higher difficulties are practically immune. Might grab enchantment focus and go with hold spells. Those are will and might also be auto-hit/crit. Good pairing with touch of idiocy.
Ray of Exhaustion is fabulous. -6 str -6 dex and slowed. It does have a Fort save, but with Spell Focus or Necro Lore items, it matters not so much. Stacks with Ray of Enfeeble too 
Touch of Idiocy followed by Contagion: Mindfire was a favourite combo for a while.