My friend Cat posted about a recent ranking of Universities worldwide. UC Berkeley is ranked number 4 in the world. I looked at their ranking criteria... and guess what... 80% of the criteria is based on researchers and their research.
All this ranking means to me then, is that UC Berkeley is a great research institution. It tells me nothing about the University other than they have a faculty that is very much concentrated on research. In my experience, these researchers don't often make the best professors. Some of these professors are so brilliant in their field of expertise that just trying to keep up with their thought process is next to impossible, and their exam questions involve making intuitive leaps to solve.
As much as the research ability of universities are touted, that's not the reason most students attend university -- they go there to learn, and that message is all too often lost amidst finding out who they really are, in between the parties, the raves, the part-time jobs, joining a frat or a sorority, the never-ending soap opera of dormitory life... It's only a small amount of students that participate in research at any university, so for most of the student body, these rankings hold little signifigance in their life.
The rankings are also biased towards the sciences. Although they do have data for the social sciences, they completely ignore the humanities and other subjects that are studied in colleges/universities. I think this goes to show the emphasis placed on science and technology to the neglect of the other areas in academia, especially in Asia today.