Kim B got it right when she said Chapters did a phenomenal job restoring the old Runnymede Theatre. It remains a beautiful monument and you can still see so many of the original flourishes and design details inside and out. They have a really good magazine section in the back, on the old "stage" area that you can browse for hours without any interruption. I also enjoy the velvet theatre seats along the side walls, and the second floor mezzanine is good for reading in peace as there are small tables to sit at.
At one point there was a Starbucks Cafe upstairs but that has since been removed and replaced by a general health section.
There is also a good single washroom located near the front of the store that you can easily use without any fuss. If you're shopping in Bloor West Village and need to take a quick bathroom break and don't want to buy something, use this washroom.