Well, which one depends really on what you are doing BC's for. Is this for some equipment you need, or to make gil? If its just for making gil, here is my experiences with the BC60's:
Wild, Wild Whiskers: Drops Pentinants Rope. Last time I did this BC, Pentinants rope dropped 2/3, and walkyre's mask drops regularly as well. 3 people. I went in with WHM, BLM, and NIN. The torami does a lot of -ga spells, need to run away when his whiskers twitch. Keep barthundra up, and have whm ready to cast stona when the tank gets petrified. I am not sure how pld would work in this bc, but can try.
Dismemberment Brigade: Drops Spectacles about 1/6 (In my experience). Kinda need PLD tank on this one, as well as a sleeper/backup sleeper. Basic strategy is silence the blm first, then sleepga and pick them off one at a time. When MNK uses 100fists, pld needs to kite, blm bind and melee's stay out of range, or sleep him until the 2hr wears.
Legion XI: Drops torques (enfeeble, elemental). Need sleeper, prefer BRD for sleep on this one. Same strategy as Dismemberment - silence blm, then sleep and take them out one at a time.
Celery: Drops Evasion Earring. 3man bc. Went in with RDM NIN THF. Each ghost is susceptible to one thing. Is pretty easy as long as the mage stays out of AOE curse range. Could use WHM instead of RDM if WHM brings juices and/or pots. I can't remember which ghost the tank picked, maybe there is some research elsewhere on the web.
These are the only one's I have tried. Hope it helps!