Warning - Contains Minor Spoilers
The story of Hellsing is absolutly obsurd. That's the best way I can possibly describe it. The story starts out exceptionally strong, and if I were merly reviewing the first 3 episodes, I would be inclined to give it an 8.5 or 9 for this section. However it seems like after this point in the OVA, the authors hired a street vendor to load a gun with plotlines, shoot them about, and pick them up randomly. Eventually the main premise of the show becomes Hellsings vs. Nazi's Vs. Irish/Catholics... to make matters worse there is virtually no back story on Alucard, or anything else for that matter. And it was inferiorating watching the three episodes that basically didn't have alucard in them. The plot certainly could have been better.
I have no real problems with either. The music is decent, the dubs are decent, and overall the animation is pretty good considering when it was made.
Lets be completly honest, the only reason this show is even decent is because of the characters. Alucard is the most badass character I have ever seen in a TV show, period. When he gets in a fight, he doesnt just defeat his enemies; he completly destroys them. I wouldn't mess with this guy, you wouldn't mess with this guy, Chuck Norris wouldn't mess with this guy. And thats the best way I can sum him up. I mean the guys name is Dracula backwards... Not to mention they found the perfect voice actor for this role, so hats off to them for that. Aside from alucard, there are other good characters as well, and there all unique.
If you could absolutly care less about story, and just want to see a lot of action than this is a show for you. I would say it's worth watching, but only because of the characters. I'm giving it a 7.5 just because of that reason. And i'll leave you with my favorite quote of the show...
Valentine: "Your just a hellsing dog."
Alucard: "Im just a dog? Well than you're dog food."