Better yet for Blade, actually play Vampire: the Masquerade. The sourcebook Time of the Thin Blood actually has rules for playing a half-human, half-vampire. Blade has vampire clans, V:tM has clans. Blade is a raging engine of death, and the Vampire rpg has plenty raging engines of death. I think it's perfect.
Anyone who wants to knock the Storyteller system can send me an email, instead of turning this nice, fuzzy thread into a battleground. Don't bother even with the email if you haven't played the game.
As for Spycraft, I have the game and it has absolutely no supernatural elements whatsoever. Yes, high-level characters can do some wicked only-in-the-movies stuff, but nothing not technically possible.