in fact all don't really offer good spotting places. Only three hotels could offer some view of the airport:
1. Sheraton Hotel: the most expensive and hardly andy views since the main termina (1) is in front of it, so maby only at the top/roof. Not recommendable
2. A new small hotel was recently opened: Phoenix Hotel (Steigenberger) in the old US Base (south of the airport) it gives some view to the runways 25R and L mainly to 25L. It is by far the most close hotel to the seen. It can be reached vis the Autobahn 5 direction Basel, get out at ' US Air Base' and you have the famous spotter hill just about 500 meters away (the one wehre you can view landings on 25R and 25L)
3. Steigenberger Avance hotel: if oyu go to the top (Swimming pool area) you have can see the birds landing at 25R
If at all, i would recommend number 2, steigenberger Avance, though there is hardly anything else there (no shops nothing!)
They have a shuttle bus from Terminal 1 and it is the less expensive one from all.
If you need more information give me an email