I think that there are comparison charts on this forum (on this page actually). I'm fairly sure that if all you want is the *G card and benefits then Aeroplan is quickest at 35k miles.
It's never cut and dried, though, so depending on your travel patterns, airlines flown, class of service, desire for benefits beyond the 'gold card' (actually the Aeroplan card is blue) and ability to redeem miles.
Dr. PITUK