I'm going to go and change the question a little to be "which gamer changed the way I look at gaming?" so I can address Wil Wheaton.
Up until recently, I'd been a real "old school gamer". Not in the grumpy only-plays-1st-edition-D&D way of being an old school gamer, but more in the style of play. Then, I saw Titansgrave - The Ashes of Valkana. There was a moment early on where our team of intrepid adventurers find some treasure, and instead of rolling on a table, or looking it up in an adventure, the GM (Mr Wheaton) turns the tables and asks the players - "What do you find?"
What the hell? I mean, trusting your players with that kind of decision was a real revelation. My old gaming group when we were kids would have been - "Well, I find a +5 holy avenger, or a full set of magically enchanted full plate armour."
Certainly changed the way I looked at running a game.