It's not hard at all to put on a tourist cap, Toronto has something new every summer. No, I wouldn't reccomend a visit in the winter. We've got great festivals from a fringe theater festival, to Caribana and a dragon boat race. The club scene thrives! The view from the CN tower at nighttime is great, you can totally find Chinatown. Baseball games can be a lot of fun and cheaper than a movie nowadays....
Favourite spots:
The Harbourfront has cultural festivals happening every weekend. You can catch good African, Asian, and Latin American food and music. I love people watching at the Cafe Diplomatico on College Street. Kensington Market has all sort s of fresh fruits and foods and vintage stores to pick from and it's right at Chinatown (you can bargain at Chinatown!!).
What's really great:
the subway system is fast and takes you anywhere you want to go downtown. there's all sorts of ethnic shops and restaurants polite and friendly locals :)
Nightlife:
Just stroll down Richmond Street in downtown, there's all sorts.