Booglebox
TFC Käufer - Went to their presentation and while I know that you have to be careful with what they tell you, they seemed very organized. The school isn't just a standalone, tiny flight school, it's owned by a freight company that also operates flights and is very successful. So if you don't succeed in finding a job after your training, you might be able to join them, even if it's not a job in the cockpit at first. You have a company behind your back, which is always a nice thing to have. Plus, they've been training pilots for a bunch of different airlines, such as Air Berlin, Condor and Aerologic. I liked their campus and the owner, as he appeared to be very down to earth when I met him. Unlike others, he didn't try to sell his product, instead he focused on critical questions and explained to us that the current time is indeed problematic. I also had some special requests and he took care of them immediately.
RWL - I haven't talked to them very much and I didn't do any of the testing that is required to start flight training there. But I've talked to a lot of flight students who will start or already have started flight training there and they all seem to be happy. It's probably one of the most popular schools in Germany, in terms of quality. The selection process is supposed to be rather difficult, compared to others, which personally gives me a feeling that they truly select people based on their skills, instead of just taking anybody and get their money. They seem to have quite a long history in which they were a successful flight school.
Horizon - This is a difficult one. It's ridiculously expensive and as far as I know, it's not as popular as most other schools out there. But the two main things that convinced me were that they have contact to Airlines, such as easyjet and Helvetica, who will come to the school at some point and test all the flight students, if they wish to do so (which of course they do). Once the results are in, they get accepted or rejected. And in the likely case of being accepted, you have an airline job immediately - even though you're still a flight student at a private school. Essentially it's a mentored program but with extra steps and also good airlines. The selection process seems to be quite difficult as well and I was ready to go for it, but I simply couldn't afford flight training there, so I didn't even bother with it. For most students this wouldn't be an option, simply because of the cost. So it's either for rich people, or people from Switzerland, because as far as I know, they get a lot of money from the state if they start flight training, so it's much more affordable.
I went to a bunch of others and even did some of the selection processes and succeeded, however in the end none of them truly convinced me.