PhD - Well known professor or well known school? What is more valuable broadly speaking (assuming all else equal):


A PhD from a decent school (top ~100) with a very well respected (but not famous) professor; say for example the head of department
A PhD from a top school (top ~5) with a young academic or substantially less reputable professor compared to the other school


In my case both are funded, both projects are good, and I can see myself working with either academic. Is there a broad brush-stroke "rule" as to which degree is more valuable for my career?
I can't see how either would be preferable to the other. What matters more to your career is what you do with the opportunities you have. 

And note that disasters can happen even at the most prestigious levels. 

Do good work. Make lots of professional contacts.