I just found out that in Sweden there is an old Boeing 747 turned into a hotel. Where else in Europe can I find something like this? The closer to Germany, the better
In Netherlands there is this Airplane suite
The entire airplane has been converted into a single luxury suite for two guests. This means you have the complete craft at your disposal – including its top-flight facilities, which include a Jacuzzi, separate shower, infrared sauna, mini bar, 3 flat screen televisions, blu-ray DVD player with a comprehensive collection of DVDs, a pantry with oven/microwave combination, coffee and tea maker, free wireless internet, air conditioning, etc.
PRICE: An overnight stay for 2 persons including a luxury breakfast costs € 350. The airplane is available to you from 15:00 on the day of your arrival to 11:00 on the day of your departure.
There's also a sneak peak video featured by the BBC
Just recently (yesterday), a hotel in Vlaardingen (close to Rotterdam) opened, and they also have a plane to stay in.
The website is only in Dutch (so far), but to summarize:
The room is suitable for 2 to 4 people, and the cockpit is equipped with a flight simulator. Pricing starts from €290 for a weekend.