Ottawa overnight?
I know I would not go downtown for a 10-hour overnight!
The Hilton is the only hotel @ the airport. Rates aren't great ($145?) but the shuttle is free.
IF you do decide to go downtown, I recommend 2 properties within easy walking distance of the By-Ward Market (a k a night-life):
- Fairmont Chateau Laurier;
- Westin Ottawa
Allow 15 minutes for airport commute via taxi, 30 minutes via public transit.