<p>-Which is the best in terms of Physics?</p>
<p>From what I have read (Im applying to all of these except Brown, but for Computer Science *G700 in Imperial i believe) Cornell and Columbia have solid science programs, however Brown and Dartmouth gives you the ability to chose how to go about your education as they are much more flexible. Imperial probably has the best physics after Cambridge in the UK, but has a lesser research opportunity for undergrads and a much more rigid curriculum. For me the order would be something like:
2. Cornell, Imperial
3. Brown, Penn,
<p>-Which has the best prestige and is most famous internationally? Which has the best job prospects worldwide?</p>
<p>Worldwide? Undoubtedly Columbia. But worldwide does not matter, what matters is what you want to do (in terms of business world, research and development, teaching etc.) and where you want to do it.
Imperial if you plan to stick in Europe. Columbia if you want to come to the US or Asia.
As for joining the job industry, if you are headed for a career in the business or industrial world, Cornell and Imperial will give you the most solid education as a professional. For Research and Development, Brown and Columbia would set you up early with opportunities that come with their endowments, and a more well rounded education. If you plan to take physics and combine it either with management or engineering in a post graduate study/continue your education in a different yet related field, go for Penn or Dartmouth. </p>
<p>Best of luck!</p>