2012 "Moarfish" build is on 10.11.2 (finally upgraded from 10.8)
2013 Macbook Pro Laptop is on 10.10 (too lazy to update so far)
2010 iMac Kitchen computer is on 10.10 (waiting for SSD arriving in about 2 weeks to update)
2012 iMac Second desktop is on 10.10 (waiting till after business busy season to update, dont want to break anything)
2007? Macbook Media PC is on 10.6 (it can run 10.7 but the screen saver and remote dont work well, so left on 10.6)
My hackintosh is now 10.11.2 but was on 10.8.x for a long time. I found that 10.9 and 10.10 were not as stable. Clover pushed me over the edge for 10.11 and got a number of benefits from it, and the problems are all minor (audio must come through monitor/usb, mouse cursor occasionally flashes up double the size it should be).
EDIT: *facepalm* turns out the "mouse cursor occasionally flashes up double the size" is a feature in El Capitan to help find the mouse. I guess I just move too fast!