Not just any goal like sports or robots, but a motivation related to girls.
IE: Ai Kora with hachibe, or Donmai Princess where teh main hero has to win the affection of his fated lover in a past life or iketeru futari, where the main male is head over heels for the main girl. The more interesting the motivation, the better...

Okay more into action than romance but here's what I can think of that may interest you.

Angel Sanctuary - Goal is to rescue his sister who is also his lover but things get very complicated. Great manga.

Akuma no Ororon - Goal of Ororon is to stay alive and protect Chiaki and his life with her. Easier said than done but a great romance story.

Vampire Juujikai - Goal of the Vampire King to to find his Queen. Won't spoil it but has some great twists despite only 15 chapters so far.

Vampire Knight - Well don't think I can say for certain what everyone's goals are since things keep developing but good romance.

Kekkaishi - Suppose the goal of Yoshimori to to protect his crush Tokine, not that she really needs it.

Tokyo Underground - Goal of Rumina to rescue Ruri

Erementar Gerad - Goal of Coud to protect Ren

Fushigi Yuugi - Goal of Tamahome to protect Miaka whilst hunting for the celestial warriors.

X - Incomplete and on hiatus. Guess you could say Kamui's goal is to create a good world for his childhood sweetheart.

That all I can think of right now. Like I said, not really a romance person but some of these have great love stories in them, Akuma no Ororon and Angel Sanctuary are especially amazing.

The pen is mightier than the sword...and considerably easier to write with.

more clamp:
Tsubasa Reservoir Chronicles - Syaoran runs around collecting feathers for Sakura (and spoilers/plot twists add more layers of hero for love)
Card Captor Sakura - Syaoran is after cards, fights Sakura for 'em
Chobits -Hideki gets involved in everything 'cause of Chi/trying to find out more about Chi
Kobato - main boy is working zillion jobs to pay off debts of (well I think love interest)
Ok, throw a stone and just grab a Clamp work and you'll hit something related

Midori no Hibi - hero's goal is to get love interest off his arm (and get a girl friend)
Superior-hero's goal is to kill the love interest (and he doesn't know it)
Basara basically similar to above (and again doesn't know)
Love Hina-the whole point of getting into Todai is to fulfill a childhood love promise

The World God Only Knows - hero's supposed to seduce girls to excise demons (though not so romance)

I don't have much to suggest, but you could try Yakuza Girl. It's male lead is steadfastly determined to make the female lead his wife. One of the most goal oriented in that way shounen protagonists I've seen.

I can't think of anything else to suggest; I don't read much romance. I'll second Superior and Vampire Juujikai as they're great manga though.

Tree + Taco = Tree taco.

Inuyasha?

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

i 3rd Superior

and mention
Code breaker
Ann Cassandra
Full House Kiss
Help!!
this one might work 2 Kanojotachi no X-Day
The One

idunno if u dont like BL but i'll add it anw Asterisk
Gohou Drug << u dont really see BL here and as many of clamp's works its on Hiatus
this is all i could think of =/

** "It's so warm that, Before the snow has a chance to stick, He melts it for me." **