The drink deals here are incredible; I don't know of another place in Toronto that compares to Wide Open on that front.
I went to the Thursday Happy Hour, where everything is $2.75. That is a ludicrously good deal for this city. It appears they have similarly mind-blowing deals every night of the week. Add to that the fact that Wide Open is in a great location, in close proximity to other Toronto nightlife, and it really becomes a no-brainer where you should meet up for a pre-drink before going somewhere else to dance/see a show/etc.
The place is small, so expect to stand if you show up at the wrong time, because people in the area all seem to be well aware of the deals here and will crowd the place accordingly. But there is a decent amount of space and some good seating to be had if you're punctual.
The aesthetic is cool, with a huge graffiti mural running the length of the wall. Graffiti Alley (the actual name of the street) is right around the corner and was probably an inspiration.
Again, and most importantly, this is your one-stop-shop for cheap drinks, and that is by far the biggest strength of Wide Open.