I'm fairly certain that the first gaming content that I watched was by Tobuscus (Toby Turner) and his Minecraft series. Later I started watching a variety of others like SethBling, Lordminion777 and Markiplier. Somehow I drifted away from watching gaming videos, but I'm curious who your first creator was.
(UGH! Researching this post, I looked up Toby Turner and found out he has been accused of rape twice, of cheating on everyone he ever dated, and of having drug problems. So much for my fond memories!)