Ah the glories of Wikipedia, besides the threads that have been posted any suggested Seinen Manga?
I am partial to Naoki Urasawa manga. Monster and 20th Century Boys/21st Century Boys are classics. I'd like to read Pluto, his most recent title, but it seems to have been dropped by it's scanlaters. Most recently I've read King of Thorns, it's been scanlated up to chapter 23 and is very good.
Berserk is a Seinen one but you probably already read it.
Sanctuary is a fantastic one too.
There alot more great Seinen series, i just need to digg them out later.
HAHAHAAHA i am stickin with My balls it is more of ecchi but oh well
would gantz be consider one or is it shounen?
luv it but kinda don't like whats going on currently in the second part...i missed kei (main character in first part) so much, he's the best character out of the whole manga...well thats what i think
For a list of Seinen you should consider using the search function at www.mangaupdates.com, for me I personally loved Ai-ren and Saikano (end of the world madness), Kodomo no Jikan is another one if you're after perverted, and i mean perverted loli humor