Le Centre Sheraton has always had the best Marriott/Starwood Executive Lounge in Montréal. The Delta, airport Marriott and Sheraton are weaker, IMHO. AIR, the Renaissance rooftop bar, however, is always lively and very popular with the afterwork 5 à 7 crowd, especially on Thursdays. Not to be sexist, but the female bartenders/servers tend to be quite fetching.