adren+regen+focus (it is best fade for me)
adren+cara(siege)/redemp(classic)+focus(siege)/cloak(classic) (good for charging and attacking i used to use cele but that is for devouring only:/ and when i see only devour onos its sad imho)
as Lerk i always go Cele+Cara+Focus --> handy for JPers, just move up,down,left and right to dodge and when I get close to them their usually dead
as Fade i USED Adren+Cara+Focus but when you get a hang of it i recommend changing to Cele+Cara+Focus. and when you got the 2nd hive so you can Metabolize to get your energy back
i don't play Onos that much so ask someone else for that
with NS maps get a MC first and then Silence with Skulk!! you can sneak up behind marines and parasite him ONCE and bite him TWICE and he's dead =)