LOVE
Whoever does not love, does not know God, because God is love.
I found out the answer - water.
Of course I didn't think it up but a NatGeo show pointed out the fact that without water all life on earth would end so I guess it would render all the other answers a moot point.
I like love and life better but in the end...I guess I have changed my personal answer to that.
Compassion (according to Buddhist this is the main requirement for enlightenment, and thats what I want)
I like the way you think girl!
SEX
(Hey, it belongs in this list SOMEwhere..it's on the first row of Maslow's Hierarchy for Pete's sake .. and Pete is very grateful too.)