The Delta Airport Hotel is a nice hotel, that happens to be directly across the street from the departure gate at YYC. I have stayed here twice on the front and back end of business trip to Medicine Hat (a long 3+ hour drive across the fruited plain) and have joined friends for a drink in the lounge prior to departure. I also remember a very kind hotel attendant who let me park my rental car in one of their limited spots while I was waiting for a colleague to get back (late) from his day skiing at Lake Louise.
During my sleepovers, the rooms were comfortable, clean, and safe. Service was friendly and helpful and a separate parking area was available. You might need the car if you're staying here longer than to make a travel connection. Terminal entertainment options are limited and there is a substantial commercial area (including a Chapters Book Store) very close to the airport.