i will judge based on the ODs that i've tried:
SD1
Barber LTD
OCD v3
OCD v4
ZDC
DZound
Fulltone Fulldrive 2
G2D Custom OD
BB+
it's a tight battle between the BB+ and G2D Custom OD but...
strictly OD, i guess the G2D Custom OD wins it for me.
had i not tried that, the BB+ wins hands down and we're not even talking about versatility yet.