My top seinen is still Bitter Virgin right now.
I admit to not having read a lot of seinen yet, though.

If you've ever thought or said "Nice Guys finish last" and really meant it, then you should probably read this LJ post by DivaLion. It's incredibly insightful whether you're male or female.

From a bumper sticker I like:
"If you're gonna ride my ass, at least pull my hair."

Erm... I feel kind of lazy to name all the seinen I like...
I'll try though.

Those are the ones that I'm more fond of, from the other seinen titles in my lists.
(order doesn't really matter)

Yokohama Kaidashi Kikou
Yotsubato!
Vinland Saga
Berserk
Iryuu - Team Medical Dragon
Blood Alone
My Girl (SAHARA Mizu)
Bus Hashiru
Nanairo Sekai
Hourou Musuko
Hoshi no Koe
Eden
Endo Short Stories the god one was just so great...
Emma + sequell which is great. (Emma Bangaihen)
Otoyomegatari only one chapter, but damn...
Homunculus
Blame!
Chokotto Sister
Kiseijuu
Nijigahara Holograph
Ichi the Killer
PositioN
Majo

Mmmm... I've probably missed some....

Hrodulf and Bjornolfr, you will not be forgotten.
[img]http://i411.photobucket.com/albums/pp199/SyberAngelGabrielle/couplesig.jpg[/img]
[color=black]And if the world were black and white,
you would be my rainbow in shades of grey.[/color]

Click 'n Play!

If I had a fantasy self, it'd be a tentacle monster.

I don't know if I watched/read too many of these days but the ones that have and are to my knowledge definitively identified as seinen are among my favorites...

1. Mushishi (perfection in every sense of the word)
2. Moyashimon (funny, odd, slice-of-life)
3. xXxholic (mysterious, magical...although the latter manga chapters have started to grate on my nerves a bit on account of the usual CLAMP cliches)

i dont read that much seinen, but my favorites so far are

Battle Royale
Berserk
Bitter Virgin
Akumetsu
Gantz
Mushishi
Hellsing

As of now, these series are in my top 10 choice:

Liar Game
One Outs
Tajuujinkaku Tantei Psycho
Jiraishin
Cesare
Vagabond
Palepoli
Takemitsu-Zamurai
Kokumin Quiz
Marie no Kanaderu Ongaku

Whether we fall by ambition, blood, or lust,
Like diamonds, we are cut with our own dust.

i have few xP...

1-st Golden Boy
2-nd Berserk
3-rd Gantz
4-th Chocolat
5-th My Girl(Senien)

thats all for now...

Shin Angyo Onshi
D-ASH
Zero
Haruka na Machi e
Bio-Meat: Nectar
Gantz
Threads of Time
Akumetsu
Aiki
Übel Blatt
Love Junkies

Can I put more than 10?

If so

Tenjou Tenge
Kamen Teacher (FUJISAWA Tohru)

Etc...

[img]http://fc05.deviantart.net/fs14/f/2007/026/1/1/Into_Werewolf_by_AbyssWolf.gif[/img]

[img]http://img.photobucket.com/albums/v168/Tank_soldier222/Into_Werewolf_RETURNS_by_AbyssWolf.gif[/img]

I'm pretty sure from the lists I've seen, Shin Angyo Onshi, Tenjou Tenge, Skyhigh, Alive, Ubel Blatt, and Gantz can be added to the popular list.Those are my favorites, but I hope these others add to the lists of others:
1.Bestia(be warned, i've only seen the first 3 chapters.hoping for more)
2.Kanokon(in my top 20, but most of the top are taken)
3.Nana to Kaoru (hilarious circumstances, but it has started to develop lately)
4.Mysterious Girlfriend X (similar to the last one, but takes it way further)
5.Sundome(same as Nana to Kaoru, but the roles are reversed)
6.Yakuza Girl(although its over, it was a great series.)

What I love about seinen is the thought provoking ideals and complex characters. You always have to be on the alert for ulterior motive, just like in real life. I hate the 2D characters in Shounen, they always only have one goal(which they tell you) which leaves you unprepared for the complexities of real life.

If you were forced to choose between sacrificing your life for your beliefs or sacrificing all your beliefs for your life, which would you choose?

My Top 15 Seinen Mangas

Lucu Lucu
Mysterious Girlfriend X
Tenjho Tenge
Black God
Berserk
Crying Freeman
Gyo
Uzumaki
Battle Royale
Afro Samurai
Onihime VS
Kamen Teacher (FUJISAWA Tohru)
Girls Saurus DX
Buddha
Kiseijuu

See ya!

Lately finished read Ubel blatt and i must add to my list ^_^..as the 6th.
so new list is
1-st Golden Boy
2-nd Berserk
3-rd Gantz
4-th Chocolat
5-th My Girl(Senien)
6 -th Ubel Blatt
7-th White Album..
8-th Black God
9-th Haru Yo Koi...
thats all for now 😛

Why isn't Japan Tengu Party Illustrated in anyone's top ten?
one of the best manga I've ever read...

otherwise I would be like, 20th Century Boys, Vinland Saga, Berserk, Planetes, Blame, Blade of the Immortal, Mushishi etc... but then everyone knows they're good. Must get around to reading Monster..

Akira is probably seinen isn't it?

Also things like Gyo, which is horror but probably targeted at Seinen readership..

Dangu
Shin Angyo Onshi
Kurokami
School Days
Tenjho Tenge

Those are the ones that really stand out in my memory, immediately.

Listen here
Livin just to keep from dyin
[img]http://imagegen.last.fm/TheDarkTen/recenttracks/imgooley.gif[/img]

I haven't read much seinen, but I liked these:

-Until Death do us Part (amazing)
-Vagabond
-xxxholic

[img]http://i257.photobucket.com/albums/hh209/kahoko_photos/MUsignature.png[/img]

Nijigahara Holograph
Homunculus
Soil (the story looks interesting. reminds me of Parnoia Agent anime. too bad scanlation is frozen)
Ciguatera
The Laughing Vampire

currently...

1. Claymore

2. Mother Sarah

3. Red Eyes

4. Gantz

5. Ichigo no gakkou

and ofcourse, Mephisto

[img]http://i268.photobucket.com/albums/jj11/obinrobin31/FINISHED2-Roger.gif[/img]
[color=black]The Hidden Agenda=[/color][color=red]Gol.D.Ace[/color]

[color=black]This Week's favourite:[/color]
DoLL (Okado Tatsuya)
Xp