IT or HFH or Allure. Read the many reviews from these places, check their websites for schedules, pick an attendant you think you want to see and make an appointment.
All these places are not too far off the 401 or the 407.
Part of your decision may be based on the time you're heading through Toronto:
--If rush hour has started, stop at IT for a relaxed slow hour and let the rush settle down before you drive through.
-- If you're ahead of rush hour you may choose to get across town and stop for an hour at Allure to ease the stress from your drive to that point.
-- If you're going to be in the midst of rush hour stop at HFH. You will have built some stress from the drive, can get that relieved and should have clearer sailing the rest of the way home.
Where ever you go you're sure to have a smile on your face for the remainder of your drive to London.