If I were writing a Guide To Toronto In The Summer, page one would be about me and my fantastic guiding credentials, and page two would be about the Black Bull patio.
Put simply, it's the place to be and be seen in Toronto in the sunny months - always packed to the brim with locals who enjoy the fine beers and simple, satisfying burgers this place delivers. If you're looking for fancypants service or fare, this isn't the place for you - but if you're into a chill afternoon with your friends in the sun with some bevvies, you really can't go wrong.
Bonus: it's a fine place to people-watch as the patio is situated in a prime position on Toronto's Queen Street West - tons of foot traffic means that whatever way you swing, there's great eye candy passing by and never a dull moment.
One warning: be prepared to wait in line, even if you're just a couple - especially around prime times. If you number more than a couple, be prepared to wait...a long while. One beer tends to lead to another, so patron turnover isn't super swift.