Though BECK is my favorite of this group, AIR's romance between Yukito & Misuzu was beautiful, especially in the movie. <3
Though GSD and Eureka Seven are very close. Both series took the time to develop romantic bonds as well as individual characters.

Series I Didn't Include Because I Prefer Their Manga- Elfen Lied, Chobits, Chrno Crusade, Mirai Nikki, Yamato Nadeshiko Shichi Henge, & Vampire Knight.

I usually don't care for series that use romance as a main genre, that might describe my dislike for most Shōjo series, but using it as a sub-genre, like in Gundam SEED Destiny, is alright with me.

Sorry this poll came out of nowhere, I got bored.

In my top 10.

I guess Beck

Also Kimi Ni Todoke, Toradora, Anohana, and Sekai Ichi Hatsukoi. =) Haven't really seen the others but I've been meaning to watch Eureka Seven.

The best!

Also Sola.

Also Air, Toradora!, AnoHana and Eureka Seven.