I love threads like this!! Toronto is an amazing city. Here's some ideas:
* Second City - Improv Comedy Stage Plays. Truly hilarious and in the middle of the theatre district, with lots of really nice restaurants and theatres showing plays. Second City is only in Chicago, Hollywood and Toronto - so I highly recommend a visit. There's also free improv after the last show as well.
* St Lawrence Market - really nice to walk around, see restaurants, architecture and walking distance from Union Station and the heart of Downtown
* Distillery District -
http://www.thedistillerydistrict.com/ - Outdoor district that features cobblestone walkways, tons of amazing lounges, bars, brews and restaurants. My favorite is the Boiler House
* Real Sports Bar - Right next to the Air Canada Centre, it also won an ESPN Award for Best Sports Bar. But go in advance, great place to watch a game and tons of beers on tap
* All the mini villages - my favorites are Danforth and DVP (Greek), Gerrard and Coxwell (Indian). Tons of others but these two are my favorites.
* Wings - Best wing places are Duffs Famous BBQ, All Star and (franchise) St. Louis in my opinion. Everyones got their own.
* Yonge and Dundas Square - a lot always going on there, and good shopping right across from the Eaton Centre.