I have watched the english dubbing version and i have the japanese subtitled version on my hard drive, both are superb. At times, sure the animation is a little ropey, mainly on close ups of expressions but you generally get this most japanese anime, that gives it a little bit of anime character. Thats what seperates it from the likes of toy story and the like.
As with much of the anime genre, there is a deeper meaning to all of this, it is not just gore, vampires and killing them all. With the rigt mind set, it is spiritual, the characters teach you, each character being strong in the personality that they have.
The story is basically about a vampire hunting agency refered to as the "hellsing organisation", this organisation have a secret weapon who goes by the name of Alucard (read it backwards and mixed with the first episode all will become clear). The leading ruthless arrogant male character is somewhat unbeatable, no weaknesses only strengths and lots of them. The story however is not about him so much as his apprentice "Police girl" or Seras Victoria. He trains her into the female version of what he is with tough love but hidden respect. Yet Alucard is still a star, you still enjoy watching his destructive arrogance and seeing him reveal yet more power to us and revel in his task of ridding the world of vampires often killing them slowly and taking the time to let them think that they have killed him and then annihialating them with his 2 foot gun or his alchemic hands, just to demonstrate his power.
All in all, well worth a watch though it may not be every bodies cup of tea, i advise you watch it under the influence of an intoxicating substance...everything becomes more interesting when that happens. Especially spiritual anime.