A cute little hole in the wall, Sweaty Betty's is extremely popular. Being packed may be a by-product of it's size (RE: not big) but more likely it's the fact that this place is totally awesome.
I was first taken here by a friend who had quickly made this his 'place to go.' With reasonable pricing, good music and a generally friendly crowd (important considering you really do physically bump into everyone at least once in a night) make this a fun place to be.
The bar itself, or rather what you can see (perhaps the owners are choosing to save electricity by keeping most of the lights off?) is a real homey feel. It's lots of wood, with old chairs and tables: an easy place to claim as your neighbourhood spot.
It's one of the bars on Ossington that seem to be taking over the area. This place has done a great job to change the face of Ossington and Queen, not through any sort of community outreach, but simply by providing people with a cool place to hang out, and through that showing locals that they didn't need to travel to other areas of the city for a fun night out.