For an overnight stay before an early flight, this Moxy hotel is a good option.
It's a 5-10 minute shuttle bus to the 'Easy Access Parking' facility nearby, which you take from the bus stop at the airport. You really have to pre-book this for an early morning departure so they know you're coming (and to make sure there's space on the bus).
Comfy beds, good shower (with conditioner, hooray!) and nice staff.
In the local area, there's the hotel bar with some food options, good music and table football, one pizza restaurant and nothing else. If you're coming from the airport - stock up at the Rewe mini supermarket in the basement first.