Company ranking

Hey, 
I'm always looking for an internship in Europe, and I don't know that many investment banks where you can do an internship, or how they rank in comparison to each other. Especially for the German market. But I have already read on the internet that there are company rankings and suchlike somewhere, where do you get them? 
Or can someone here who might have such a list send it to me, that would really help me a lot. And I would really be very grateful. Because I always have a bit of a problem with that, thank you :)