i agreee that it really, really does seem to be the MO for this threesome. hmmm, i don't know if i have a favorite scenario per se? usually i am 'omg, i didn't know i even wanted that!' until i've read it. *sigh*

but for bb!ot3 one of my absolute favorites is: Some Are Born To Sing The Blues (http://mariannafic.livejournal.com/34476.html)

and for just regular ot3: Both Sides Now (http://sunday-porch.livejournal.com/8687.html)

both fics come at it from slightly different angles than i usually see and it's fabulous! but, as always, that's just my opinion :D