Well.... most of what i would like to suggest is already mentioned, so i will just add this.
Kimi ga Nozomu Eien (Anime)
One of my favourite heartbreaking romances

Mittsu no kokoro ga hitotsu ni nareba...
Hitotsu no seigi wa hyakuman pawaa.

• Getter Robo -

[color=green]Well i'd say Hoshi No Koe.There's not a lot of it but i like the romance in Genshiken .[/color]

Rubbers 7 is a surprisingly good one.

I like the romance in Ai-ren and Saikano both of theses titles are probably the first thing which comes up to my mind when you say Seinen Romance

Do not feed the trolls
[img]http://img517.imageshack.us/img517/5526/fireproofbyevilbug.jpg[/img]

My favorites were Saikano and Bitter Virgin. Both had extremely dramatic endings, one of which was horribly depressing, and the other surprisingly happy.

Bitter Virgin was an exellent romantic story, I also likem Saikano which was very good because the romance was really tragic.

Quote from lilchoconut

SaiKano
TT__TT

I did a double take... I can't believe it was missed

SaiKano is probably one of my favorites, but its just so tragic! The end is bittersweet..

I also think emma is good saikano was great and bitter virgin was cool too

[Life is But A Dream..]

I really enjoy Mysterious Girlfriend X (Nazo no Konojo X) I wish it was updated more often. I love the weirdness of it and the romantic ecchi feel (its more of a strange relief to my fav. drama romances)

[img]http://farm3.static.flickr.com/2777/4207527145_31aa2e1471_m.jpg[/img]

Let's not forget Koi Kaze. Though it's incest, I find it really good.

Quote from Noobsrus

I like the romance in Ai-ren and Saikano both of theses titles are probably the first thing which comes up to my mind when you say Seinen Romance

His

death scene almost made me want to cry. And it wasn't even done in a sad way. He was telling someone not to lose hope the whole time....

geez, almost everything everyone has mentioned are stuff I like too. (Like "sing yesterday for me").

This may sound kinda weird but....I think Berserk deserves a mention, aside from Gutts utter manliness the romance between Gutts and Casca was my favorite part, some of the most epic romance I've ever seen

But aside from that Bitter Virgin prolly is my favorite, it gave me a new hatred for human beings (assuming there are people who atcually do that), it really struck a cord with me, pissed me off reading that

And the mother 😕 ? Shit lemme stop, Don't even get me started on this topic

But yeah, Seinen Romance is the shit

[img]http://img40.imageshack.us/img40/4158/1205047355313.gif[/img]

Quote from smichal

Well.... most of what i would like to suggest is already mentioned, so i will just add this.
Kimi ga Nozomu Eien (Anime)
One of my favourite heartbreaking romances

Dude that was like the saddest anime I have watched in a LONG time!!! The main guy was such an idiot. He didn't even get it when he had it LITERALLY beaten into him. What an idiot.

At least he got it at the end, but it took him long enough.

Saikano
Bitter Virgin
Emma
Koi Kaze
Mysterious Girlfriend X
D-Ash
Kodomo no Jikan

I have second and third all of those.

I would also Like to add:

Suzuka
I"s
Pastel
Parallel
Ai Yori Aoshi
Yume De Aetara
and
Umi no Misaki

This is my Sig ..............................................................

Quote from firestalker

Suzuka
I"s
Pastel
Parallel

Err...neither of this is seinen...all shounen titles.

If the sea were made of Whiskey and I was a duck
I'd swim to the bottom and never come up

I've only read a few, but I thoroughly enjoyed Bitter Virgin.