I've been here twice now and will continue to come back because the clothing is great, reasonably priced and both times my service has been exceptional.
I first found this place because I had to get a new tie for a wedding I was going to in a couple of days. I tend to bundle up all my errands in the same neighbourhood so I was running out of good options to get a tie on Queen West as I was quickly approaching Ossington. Thankfully this store caught my eye and they had more than enough ties to select from. Side note: I looked damn good at that wedding!
The other time I went I was attracted by a "shirt sale" sign and was pleased to find a big selection of shirts from Penguin and Ben Sherman for only 30 dollars! I had a hard time making up my mind but the salesman was more than happy to let me try on several shirts. The place is quite small and there was only one other person there at the time, but it's still nice to have someone devote attention to helping you find what you're looking for. One beef though is they have one of those makeshift changing rooms where you are basically only behind a curtain. I don't really like taking my pants off in situations like that.
Grreat Stuff has a bit of a daft name (makes me think of Tony the Tiger) but they have really great clothes for men and apparently have some nice sales if you can wait for them. They even give you nice re-usable bags with your purchase! If you hang out on Queen West near Trinity a lot like I do then this is your spot for men's clothing for sure.