After having used Boeing(737NG), Airbus(A300-600), Embraer and Bombardier(CRJ Series up to 900) I must say - Bombardier. Very simple and CLEAR QRH. Lots of memory items but still better than Boeing(seems more their QRH is made by a lawyer instead of an engineer/pilot) and Airbus(Airbus being typically complicated).
My (very) clear favorite - Bombardier with the CRJ QRH.