The Kempinski Hotel Airport at Munich Airport is situated directly at the airport, adjoining Terminal 1 and Terminal 2. If you are flying in or out of Munich, this is an ideal hotel option. The hotel is up to the standard of any professional business hotel you would stay at in the USA, including modern rooms (with great air conditioning or heating...depending on what you need). The television has one of the largest channel selections I have ever seen at a hotel, with everything from the BBC, to Dubai Television. They even have TV CUBA! That was something you don't see everyday.
The staff are friendly and professional, with a level of service that rivals any of the great 5-star hotels in Europe. Don't miss the buffet breakfast, as it's a treat of many different foods, including many Bavarian favorites. They have the usual American fare (bacon and eggs), but skip that and try some of the home-made Meusli, along with Nurenberg sausages with spicy mustard. And, the bread selection is never-ending.
Don't just use this for airport trips. Use this hotel for your stay in Munich. The S1 and S8 trains (subway) costs 11 Euros for an all-day pass on the entire Munich transit system. Take the train into town, about 35 mins, see the sights, then come back to the hotel. You will save some money and have the best of all worlds.