Arguably our most influential tester at Microsoft has just created a blog. The reason i would put James at the top of the tester leader board has nothing to do with his three books on testing but rather the fact he managed to talk the XBox team into giving him access to the XBox Live Servers where he proceeded to hack the physics for the HALO game play so his character could see through walls and have bullets that had gravity characteristics that caused them "fall" into his opponents. (Think of the bullets as being magnetized) -All under the guise of helping them test their software!
(Funny thing is he still managed to lose almost as badly i typically do!)
In either case checking out his blog it is definitely worth the time!
PS I will be adding James blog to the Team Test Blog roll as well!