Keeping in mind the lower budget, I frequently book in at the Econo Lodge right opposite the Air Canada flight training centre when I need to stay overnight at the airport.

It's very reasonably priced, the rooms have been recently redone. (Thin walls in the rooms, but ask for the quiet side of the building and it's generally okay).

Free shuttle to and from airport takes 5 minutes.

Very agreeable.

Hope this is useful for the more budget-minded among us!