I think growing up with artistic influence and admiring as an adult are different... so I am going to write down the "heroes" I've discovered as an adult.
Jeff Lemire: I love his panel flow and story telling. His art is so easily recognizable too and learning that he was in film but wanted to try out comics is very inspiring. I think he believed he couldn't draw but he didn't let that stop him.
Toril Orlesky: Web comic creator of HotBlood. I never read an online comic before and hers was my first that I really kept up with. Before I wasn't interested in the idea of posting pages one at a time but through her art and story telling it changed my perspective of the medium. And I like seeing that she finished her story!
Jeff Smith: His dedication to Bone and being one of indie comics loudest voices, it's hard not to think of any indie creator who hasn't read Bone... and when you do find someone, that is corrected immediately!
Pascalle Lepas: Creator of Wilde Life. Another online webcomic that I pick over now and again. I never read through it in order, but I love seeing her interaction with fans and how she was able to turn her passion into her day job. She shows me it can be done.