yeah naruto is great for blood.
x/1999 by Clamp is chock full of blood and action. I'm not sure if it would really be classified as a drama, but the storyline is great.
I would say Hellsing or Battle Royale if your really into seeing some gory scenes
you should read Love Hina it is freaking awesome.
you should read Ai Yori Aoshi it is an awesome manga book.
Well, if you are looking for good action mangas, then stick with Hellsing, Battle Royale, and Berserk! Those are probably some of the best action series out there. Maybe take a look at the Ragnarok anime series as well.
saber marionette j is also very good series... well i likedi it anyway.