Gabe plays Clichequest, and Sir Bob is his character.
In this strip, we saw Gabe's character in an MMORPG. They mentioned it as World of Warcraft, but disregard that, it was obviously Clichequest. Now look at this The Noob strip, and compare Sir Bob to Gabe's character. Not only do they both have Rainbow Pimp Gear, they look somewhat similar.