BL mangas with good & long stories.

I Amore boy-boy, but those short 1-4 volume mangas tend to have storylines that are total crap.

A nice example is Gravitation. It was very long & had an actual story about a young man getting into the Musica business, with rivals & everything.

Kyou Kara Maou & Yami no Matsuei aren't technically listed as BL, but we all know they're intentionally gay as they can get. Their stories have intrigue, action, adventure, death, fantasy, etc. instead of focusing solely on the relationships.