Way way way back it was Angelo Manera. (You have to be very old to remember him.) But all JW's had a bit harsher personalities back then.
More recently, a CO named Frank Barr (not sure about that spelling). He was a poor excuse of a CO. They were obviously scraping the bottom of the barrel when WTHQ sent him on the road. His wife was even a worse bitch, especially to the young/teen crowd.
And even more recently, I think they all seem to be "Company Men" who know they'll lose their cushy little job if they let something slip by that costs HQ a few bucks.