Katho-chan
I only really saw one was Gravitation but I heard of another one called Loveless.
Those aren't yaoi or even Boy's Love manga. Yaoi is graphic male/male sex manga. Think hentai for women.
sweatdrop Tokyopop published Gravi as BL as a mistake, its actually a young boys {shounen} manga but just has a homosexual couple in it. In Japan its actually published in a shounen magazine not a BL mag.
Loveless is a young girls {shoujo} manga but has homosexual pairings in it.
For a series to be a Boy's Love series it has to have the relationship as the key focus.
3nodding