Here's some tips against Dwarves.
1) Take Fell Bats. If you are playing a standard game (2000-2500 points) at least two units of five will do well, maybe even three units. They are fast enough to get a charge on turn 2 (or at 3 if you are unlucky) and they will do wel against war machine crewmen. Even with T4 Dwarves are going to die or be without shooting. They can break too if your opponent is very unlucky!

If your opponent tries to shoot your bats it's okay, at least he's not going to shoot your Grave Guards with those pesky Organ Guns.
2) Purple Sun suicide Vampire, as Humaneater explained it.
3) Combat Lord (Humaneater explained this too

). I found out that this compo is the best one, good all-round Lord.
Vampire Lord
- Red Fury, Infinite Hatred, Ghoulkin
- Sword of Strife, Talisman of Preservation, The Cadaverous Cuirass
He has 6 re-rollable attacks with Str 5 (I know, Str 6-7 could be better against stunties but I prefer more attacks), every kill grants an extra attack and he's protected pretty well too. Ghoulkin is very good against stunties, who wouldn't take an extra move against a gunline?
4) Zombie walls. Units of 20 Zombies with musician at the front of units which are not Ghouls, Grave Guards for example. Zombies are cheap meat walls so why not to use them? When they've done their quest they can just swift reform and move out of the way. That or they're already destroyed, whatever.

Just remember not to take them into combat, they just bring some easy kills (and combat resolution) for Dwarves.
5) Spirit Hosts. These ones might do well as war machine hunter unless your opponent fields Thorek Ironbrow.
So that's what comes first to my mind, good luck at your games!
