I use the Library Bar as a great place for business meetings and after-work cocktails. Its a bit pricey, but the drinks are very well crafted and the atmosphere is unique. Reminiscent of old town Toronto and museum-ish empire hotel pubs, I like to think its the bar you might find Mackenzie, or Hemingway, or maybe even Brando having a drink back in the day. It can get packed on the weekends, but thankfully you can book reservations (just don't do it online). I've never tried the food, but I always see a lot of people eating.
Recommended: The 'Hemingway Mojito'...