Mayfair, Playboy, Excess, Penthouse, Rustler,
Only kidding:
here's a few to start off with
Vertical Magazine covering the North American marketplace
Vertical Magazine - The Pulse of the Helicopter Industry
Heliops
Heliops Magazine
Rotor & Wing
Rotor & Wing Magazine :: A member of the Aviation Today Network
Rotorhub
Rotorhub - News - Shephard
Defence Helicopter
Defence Helicopter - Publications - Shephard
Helicopter Magazine
Helicopter Magazine Europe
Hope this helps
Cheers