Also try the Elgin - there's usually a high star quotient for the Visa Screening room (Laura Linney, Gael Garica Bernal, Frank Gehrey, Liza Minnelli, Katie Holms (pre marriage to that crazy cult guy), Robert Downey Junior, Topher Grace, but I've also seen stars at Ryerson (Sean Penn, Claire Danes, Never Say Neve Campbell), Bader (Laura Linney, Jeff Daniels), the ROM, the Paramount (plus - Ebert in the lobby), and every other venue.
Then there are the parties - their are parties pretty much every night at Rosewater, Crush, Lobby, Bistro. Or you could just stake out the entrances at the Four Season, Sutton Place, Windsor Arms, and the Bloor Street Intercontinental.
Just remember, most of the stars will be gone by Wednesday.