Fulci is a master at combining gore & camp, I always thought. His films can be just plain silly one moment but drenched in blood the next.
@bbartok:
It's true. Mario Bava is the best, but Dario Argento is worth to considering. Lucio Fulci is another one. A good source is wikipedia https://en.wikipedia.org/wiki/Giallo. Maybe, even more sinthetical http://www.kinoeye.org/02/11/needham11.php