Definitively have a look at the Boktai games in the GBA and DS, by Konami. I'm a fan, and they are generally considered to be good games.
This may surprise you a bit, but you can try any of the Elder Scrolls games.
Morrowind has a whole expansion on Werewolves, but the regular game has vampires (I bet the same goes for Oblivion). You can contract it with some (bad?) luck and get some extra powers and drawbacks from the condition. I've never tried it much in Morrowind, but I used to get it in Daggerfall and rush to a temple to cure it before it developped fully (then I would need to do the special questline to get rid of it).
The games are quality games, I'm not sure if the vampire portions are worth it just for the sake of that. I bet there are user-created mods / add-ons that build on vampirism on them as well (you'd need to get the PC versions though).
Ivo.
Any good vampire games you know of?
I'd say the Castlevania series, especailly SOTN where you play as Alucard. But LoK especailly Soul Reaver is probably the most vampire-ish game that has great gameplay and a good story. Dark Stalkers is good for a fighter. There is a Vampire theme to Albert Odyssey for Saturn...but I wouldn't call it a vampire game.