The Grand Hyatt is good but it's really out of the way unless you're visiting one of the fairs in the TWTC (Taipei World Trade Center). It isn't in the city center. It's in the Hsinyi District and right next to the TWTC and close to the Warner Cinema Complex and the shopping centers nearby. It's a long walk from the MRT (Mass Rapid Transit) City Hall station.

The Intercontinental is OK but not within reach of anything major.

The Shangri-La Far Eastern Plaza on Tunhua South Rd. is also good but out of the way from anything major.

The Westin is new, right next to China Airlines HQ on Nanking East Road. It's not near anything worth while.

The Howard Plaza is good and the rate reasonable. It's in the Ta-an District on Ren-ai Road, close the the Sogo Department Store right in the shopping, restaurant,cafe area. It's within walking distance from the MRT Chunghsiao-Fushing Station, which is a transfer point for two MRT lines.

My personal choices would be in the old Taipei downtown area in the Chungshan District:
The Formosa Regent, on Chungshan North Road, Sec. 2
Royal Taipei Nikko, on Chungshan North Road, Sec. 2
The Ambassador, on Chungshan North Rd., Sec. 2

The above 3 are in between the MRT Chungshan and Minchuan West Road Stations. They are in the same general area but further north from the Main Train Station and the Lai Lai Sheraton and Hilton.

The best IMO is the Sherwood, but it's in the so-called financial area where most of the foreign banks have their branch offices, no shopping.

There are several airport buses that stop at some of the hotels above on their runs from CKS Airport. They also pick up from the hotels, too.