Well, Omi, you already mentioned what I would consider the goriest movie ever made, Dead-Alive. Some of the best gore ever shot! But I would add Evil Dead 2 to the list, the displays of bloody carnage, though often ridiculous, are easily some of the best, some of my favorite scenes being Ash sawing off his hand, the blood fountain from the wall, and the death of Jake.
As for other exceptionally bloody movies ( I love them too), some worthy recommendations are Re-Animator, Blood Feast, and The Gates Of Hell.