Cal Henderson, Woz and Michael Abrash. Still haven’t met any of them in person 
Steve McConnell for Code Complete and Robert Martin for Clean Code. If you have not heard Robert Martin speak yet you should find some way to. It is very inspiring to hear him talk about craftsmanship and professionalism.
I’d like to meet him myself. Great stuff.
(is it okay that I chuckled at his typo?)
Scott Meyers. Without a doubt. Showed me beauty.