Mirror, mirror on the wall...who's the worst sheriff of them all? Snort.Though this will come as no shock to denizens of cactus country, The New York Times' editorial blog -- The Board -- today dubbed our corrupt top constable, "America's Worst Sheriff." Noting Joe Arpaio's recent foray in to trash TV with the new (and soon to be forgotten) Fox reality pilot, "Smile...You're Under Arrest!," our fellow scribblers at The Gray Lady went off on Maricopa County's Pennzoil-pated law man, bitch-slappin