Calgary's business district is quite well defined. The downtown core is only a few blocks, and is quite easily walkable, even during the winter. Many hotels are tied into the elaborate plus-15 network of indoor walkways, which is very much necessary during the winter cold snaps that hit Calgary several times per year.
The Sheraton Eau Claire is on the north end of downtown, but it is connected by plus-15. This all suite hotel is on the pricey side, but the service and value demand it. It's also a nice place to stay, if you need to escape from the downtown stress with a walk by the river. The YMCA is next door, and it has a great gym for working out, although the hotel also has a workout room.
Hotels near the airport are well equipped for business. Most have large meeting rooms and provide efficient service. The airport is about 10-15 minutes from downtown, depending on traffic, so it's not a bad area to stay, even if your meetings are downtown.
The Hyatt Regency is connected to the Telus Convention Centre, and it has a nice central location. It's very easy to get around town, too, because the train station is right outside the door.
255 Barclay Parade SW
All-suite luxury hotel...
220 4th Ave SW
Many suites to choose from in the heart of downtown...
700 Centre Street SE
A great hotel near the convention center...
899 Centre Street SW
Modern, comfortable, and beautifully decorated in downtown...
209-4th Avenue SE
On the eastern side of downtown...
2620 32 Ave NE
Business friendly hotel near both the airport and downtown...
123 Freeport Blvd NE
Comfortable yet sophisticated hotel for business travelers...
110 9th Avenue SE
At Centre St
A hotel close to the convention center...
618 5th Avenue Southwest
Spacious suites and great location...
133 9 Ave SW
A Calgary landmark and a beautiful hotel...