Finally here, my fave scanlation groups - which I'll have to check soon, I'm totally out of the loop right now. All of them do Yaoi, or at least 'boys love'.
Nakama - my second, one of the most active.
Hochuuami, Trapped in the insect net
Dragonfly - born from Hochuuami, only does doushinji.
Storm in Heaven - in Italian and English.
Memory for you, Because life is filled with memories
Game over or Continue, Gotcha!
Essence of Purity - shockingly no more site, only irc at #firstname.lastname@example.org
Obsession - in Spanish and English.
Impending Doujinshi, Silly little offspring of Aku-Tenshi
My only shoujo-only favourite site:
Shoujo Magic, Got Bishies? - gigantic.
Old faves, inactive groups with still-functioning sites
Shi-Ran, The Orchid Lounge - my first.
And some other groups I've gratefully leeched from too, not only BL but also Shounen and Seinen (and maybe some more Shoujo):
Peccatore Sancturary - leeched a lot, but still a love-hate relationship.
Biblo Eros & Liquid Passion, Scanlating our addictions, one by one
Be With You Scans
Beyond the Sky
I'm not counting the many groups I've leeched from only once or twice, mind. Or the ones I've leeched from through third parties' sites.