I don't think there are any rankings out there except perhaps which places get the most grant money but wherever you go, the emphasis will be on learning the clinical radiology stuff rather than research. In my opinion there are three classes of programs: excellent, very good, and poor. The majority of radiology programs are very good with a minority being excellent and very poor. For the most part, radiology isn't like other specialties where they can work you to death with minimal teaching. There are radiology programs like this, but most of them have at least 5 hours a week of dedicated conference/teaching away from reading the clinical stuff but for the most part you're learning while looking at films and the best radiologists are the ones who work hard and read a lot away from work. There is no way to get spoon fed all the stuff you need to know during a residency.
What's best for someone like myself isn't best for someone else. I don't care for large cities, I'm not interested in research and have no interest in being at a large academic institution or plan on teaching. So for me, I've liked some of the community programs more than the university programs where the residents seemed very happy. You'll get the studies and experience pretty much anywhere so it comes down to liking the PD, the town and the other radiologists and residents.