To continue countulrich's unit discussion, there is an exhaustive one in one of the stickied threads in this forum, but below are the characters (special than normal)
Vlad von Carstein

_o A decent allrounder with am bonus to The Hunger, and a one off come alive again on 2+ if eh fails Heavy Armour and a 4+ Ward, and three Lore of the Vampires Wizard Levels. Despite this, his all-rounder abilities mean he is outshone by other characters in their areas of expertise, and therefore not always worth it. A good character, however, and fits into a 2000 point battle unlike the other Vampire Lord character. Also the von Carstein characters have fluff potential against Empire. Also the only reason you would ever take...
His wife, Isabella von Carstein (although you still probably wouldn't take her):

Hero Vampire, but her only real ability seems to be keeping Vlad alive (one Vampire in unit can geta WOund back from her magic Blood Chalice, which had better be Vlad, or your wasting her) and fighting (both get ASF if in the same combat). And she can be sacrificed to make him better (if one goes six feet under the other gets Frenzy/Hatred, nice abilities which LD 10 should ensure Frenzy's penalty doesn't apply). if Vlad dies, and returns, the rule presumably doesn't apply until he dies a second time. And if he does die, she's hopeless. Average Vampire profile (n fact, none of the vampire characters have stat bonuses), Level 1 Vampires, no Ward or amazing weapon. Works nice with Vlad, but otherwise don't take.
Mannfred von Carstein:

Vlad's get. although more powerful than his sire for some reason. Good character. powerful casting (Level 4 Loremaster Vampires and Death) and reasonable combat abilities (Magic weapon that turns unsaved WOunds into dice for Mannfred to use next Magic Phase) and extra Wounds (Armoru of Templehoth gives +2 Wounds and 5+ Armour). With Vampire Lord stats, magic weapon, loads of power dice, all seven Lore of Vampire spells for Curse of Undeath, The Hunger, 5 Wounds, shouldn't die. Best caster in the book, and decent combat to back it up. Needs 2500 points to play, but great if he can.
Konrad von Carstein: Situational grading. Usually o_o, sometimes

. Vlad should never have sired this nutter, so insane his madness is in his rules, but anyway...Loads of Attacks, with Multiple Wounds 2 and Frenzy (or Stupidity, at LD7...do the math). Unreliable, and vulnerable, but fun if he hits multi Wound units or models.
Heinrich Kemmler

_o Character Master Necromancer. Raising Skeletons above starting size is neat, although no one else in the army can if he's there (it's in the Master of the Dead rule to stop spamming, and give Zombies a place), Ethereal or Fly (but when will he need to Fly?). Ethereal Necromancer! Quite good. But then, if he needs the immune to mundane weapons protection granted by Ethereal...Wait a minute, that's because he has Magic weapon restoring Wounds to his unit of Skeletons/Grave Guards (and +@ Attacks, as he only has 1). Don't let someone take his cloak, or he's dead. Level 4 Loremaster Vampires. Relatively cheap, but that's because, in my opinion, he's average.
Krell, Champion of the Dead: o_o, to

: Kemmler's servant (he thinks) and character Wight King. Great model. Killing Blow (Heroic in Kemmler's unit) and magic Great Weapon that wounds as the game goes on. Corpse Cart can bring him back to his I5 so he gets to use his fancy axe, and his 4+ Armour is so rusted it emits a magic aura that turns Magic Weapons he saved a Wound against mundane immediately, cancelling all their abilities (although 4+, with Armour Save modification, probably won't mean anything against the Magic weapons it's useful against). Take for something of a gimmick can work.
Vampire Lord:

General Lord. Great profile (except an irritating lack of protection beyond T5) and lots of options, with Vampiric powers. Red Fury/Quickblood usually taken, but for more variety6 try Flying Horror (Flying Vampire? great. On the other hand, he'll likely be your General, so watch out) Master fo Dark Arts to for extra magic dice, a psychological power, or Summon Creatures for extra Bats/Wolves. Protect at all costs if General. Vamps, Death or Shadow. His fighting style likely won't support Shadow, so try Vampires or Death (I'd do Vampires)
Master Necromancer:

Caster. vampires or Death. Do Vampires, with some magic boosting kit.
Vampire/Necromancer: Hero versions of above. Cheaper and weaker. Vampire cannot balance attack and defense, and Necromancer not as powerful casting. Spend points more wisely. On the other hand, extra casting/chopping.
Hope this helps.
Edit: Forgot the Strigoi Ghoul King and Wight King.
Strigoi Ghoul King: o_o Despite the fluff, no stronger than regular Vampire Lords, although they can Regenerate (5+). But even without Flaming that's not very good. The Fireproof (whatever it's called) gem gives insurance against Flame, but takes up points and slots for more important things. Ironically, All Vampires and their character version (except Konrad, who had to threaten and bribe Necromancers to keep his army going) have Magic Levels and are allowed magic armour. The Ghoul King has Magic, too, but can't wear magic armour. But the others can? "shrug". That means it is vulnerable in conflict, which is where it should be, or flying alone (it can work, it seems, but I can't see how) It can take Powwers, but a limited amount. If you like them, they can work, but I wouldn't touch them.
Wight King:

. Hero. Can be BSB, which, despite what everyone else tells you, I think is useful. I'll discuss Vampire BSBs below, but the Wight King is more suitable than the Vampire hero (who can also be BSB as he is cheaper, and the -1 to Crumble is wasted if the Vampire is doing what he's supposed to be doing. Average profile,3 Attacks, Killing Blow, but average WS. He is mainly defensive, and can take Challenges for other characters (a Champion could, but the Wight King is more survivable and has a chance of doing something back). Good with Nightshroud, making enemies in BtB with him ASL improving his chances, making for a nasty surprise in a Challenge and a boost to a combat character next to him. Can take magic items to be more survivable. I'd recommend Talisman of Endurance. Okay, 5++, like on Stirgoi, but here it's backing an Armour Save up, and he's designed for survivability. Just make sure you get a Lord-level character in the army as well, as with hero levels he'd be General, which without Wizard Levels would be illegal (although I always read it that your general was the highest LD Wizard in the army, best to be safe).
Vampire BsB: Despite what everyone tries to tell you,

. Best as Wightv King, as he is cheaper, and -1 Crumble won't matter if your Vampire is doing what he's meant to be doing. It improves the long-term resilience of your unit, which Wight Kings are meant to do. One Wound may not seem that helpful, but it means one more Wound to take down next time, and may save the BsB himself, buying a turn to send something to save it. It can keep a character going, and prolong a grind. As for the often-ignored LD re-roll, if your General is a fighter, the units he'll be allowing to March will probably be within 8 inches of the enemy, requiring a LD to March, and will protect against weapons that cause Wounds by forcing LD tests. Also allows Magic banner that can switch through units (if you do have a Vampire BsB, use Shadow as his Lore, so he can switch h around units to share the Banner's abilities. try Banner of Endless rage so you can port Frenzy around (re-rollable LD7 should control it). Talking of Frenzy, if you take Konrad, the BsB can try to keep him on track, re-rolling his tests. So, all up, worth it in my opinion.