This was one of the first manga I ever started to read. It's been over a decade since I first picked it up and I still anxiously await the new volume(s) each year. The art is fantastic (the first volume features some amazing two-page spreads where something as violent as a man being quartered turns into birds... not as cheesy as that line makes it sound, I promise!) and I love going back and re-reading the series, seeing how much Samura's art has progressed.
There is quite a cast of characters in Blade, and I am the first to admit that I often have a hard time keeping up with a manga that has too many characters. Fortunately, each character in Blade is fully fleshed out, different in art design as well as thoroughly established.
I love the way this series jerks you around: at first, everything seems fairly black-and-white in a tale of revenge, but within the first few volumes you already see the main character question her own motives. You learn why the man she's hunting has done what he has done, but his side is presented in such a way that the reader isn't pushed into sympathizing with his cause. There are so many great twists to this manga, and the pacing is great. There has, thus far, been only one arc that I felt was dragged on for too long, but even then, it wasn't nearly enough to deter me from drooling for the next volume. To date, I think this is the only manga I've read that literally made me go "YEA!" out loud as I consumed it because I got so psyched about what was happening.
My one complaint? This series comes out very slowly, generally only one volume, sometimes two, each year. Still, it is WELL worth the wait!