They are all in the downtown area...
Vegetarian Haven (17 Baldwin St, Toronto)
Fresh : 3 locations (326 Bloor St West, 894 Queen St West, 147 Spadina Avenue, Toronto)
They are close to the subway. I'm sure there are others...but I can't think of them right now. I'll let you know if I think of them.
Both of these places are NOT very huge. You mentioned small celebrations...how many are you looking at?