You never know in the manga world.
I'm gonna suggest Shamo. To me, it's the best seinen manga out now. :top
Claymore is awesome.
Read Berserk... Its insane.... really O_O
Not for the weak hearted though ;)
I though id just mention "Ares" since no one else did ^^
its a really good manga revolving around some people who meet eachother as mercenaries. Not a very well known one compared to the other mentioned mangas, but imo its on the same level or even better than some...although ive gotta say that the artwork is kind of love it or hate it, but as you probably figured out, I find it rather cool ;)
This is quite an old topic...
And shouldn't this be somewhere in the manga forums?
i love few manga just like :
2. one piece
3. Red eyes
4. Shin Angyo Onshi
5. The Ruler Of Land
7. 666 satan
8. Yu yu Hakusho
9. D-Gary man
This the manga you like to read for good