You know, I've never owned a single Apple product in my life - his designs were a little too simplistic for my tastes, but my parents love their i-devices, and those products reduced my tech support calls dramatically

Love him or hate him, he was a true game changer, and his keynotes are legendary. I always anticipated seeing what he would come up with next, and there aren't really any visionaries to take his place, that I know of.
As someone else said, the good/creative ones always go too soon. Steve Balmer will probably live to be 120 :P