FAVORITE RPG WRITER...
This is tough. I like and respect quite a few in this industry. Monte Cook, Shanna Germain, Bruce Cordell, Kenneth Hite, Rob Heinsoo, and Robin D. Laws.
But in my heart my top is CJ Carella. Yes, he of Palladium Books, Myrmidon Publishing, and Eden Studios. The man behind Rifts South America 1 and 2, Nightspawn(bane), and WitchCraft/Armageddon/Buffy the Vampire Slayer (Unisystem).
He edges the other out, due to nostalgia and he ran a WitchCraft game I played in on AOL back in the mid-90's.