For human characters, I have used figures by Foundry, particulalry their Victorian bystanders and townsfolk with guns(perfect for Vic London gents and ladies) Eureka, Blue Moon, Reaper, Ironclad, Copplestone, Chiltern Miniatures, basically anyone who makes 28mm Victorian era figures. Some you might have to convert to hold stakes/crosses etc,
Creatures come from all sorts of sources, Vampires can be found in most fantasy ranges. I especially like some of the Reaper Vampires and old Ral Partha ones. Blue Moon have several boxed sets including Vampires and Werewolves. GW also have both.
Chiltern minatures have Vampires and Frankensteins Creature, as do Eureka. I am sure there are lots of others that will come to mind soon.
I really like the Westwind stuff, its a very complete range and once painted the figures look great. See Mike D. McBrice's recent posting on CIC warbands for some great examples.
Have a look at my Displaced files:
There are lots of Vampires, Vampire Hunters etc, mostly with comments to identify the manufacturer:
http://www.displacedminiatures.com/Malamute/galleries/Here are some chaps that have seen service in my games. All standing in front of the Westwind Graveyard gate:

From left to right:
Westwind, Westwind,Foundry, Foundry, Foundry, Foundry Conversion.