Check out Casa Loma in Toronto. Beautiful architecture. (They used this home for Xavier's School for the Gifted in the X-Men movies.)

Being (sort of) in Chicago, and depending on where you'll be staying, Lucky's on Clark (North Side) has amazing sandwiches. But make sure you're hungry! If you're sticking to the downtown area, there's the Adler Planetarium, Museum of Natural History, Museum of Contemporary Art and the Museum of Broadcasting.