There are a great many types of sciences you can study, and there are plenty of universities that have very good programs for each. Giving each a definitive rating is based on more than just which has the most students with the highest pass rates. This list is based on average ratings and consistency over ratings for a particular field.
Cambridge University (UK)
If you were looking to rank the world’s universities when it comes to science, then this grand old English institution would win. It has an academic record and prestige so that it matches Harvard in the US and Oxford in the UK, but it is slightly easier to get your research projects funded at Cambridge University, which is why it is currently the top university for a science education in the world. http://www.cam.ac.uk/
Harvard (US)
This is a university that is one of the most well known in the world because it is mentioned frequently in Hollywood movies. It is an excellent business school, but is also a great place to get an education in numerous sciences. You do need to be both exceptional and rich (or get a scholarship) in order to attend. http://www.harvard.edu/
Oxford University (UK)
This is yet another fantastic place to get a science education, and they excel in biological sciences. There are many student run companies related to Oxford University that are making breakthroughs in treatments for disease and illness. http://www.ox.ac.uk/
Swiss Federal Institute of Technology Zürich (Switzerland)
ETH Zürich is a very forward thinking university that is well known for its work in a range of sciences. It you are looking for more advanced courses or the chance to take your studies and your research projects into new and exciting areas, then this is the university for you. https://www.ethz.ch/en.html
University of British Columbia (Canada)
This is another university where even uncongenial thinking can still land you a research grant and the facilities you need to complete your work. It is a very good place to study life sciences and the university is very well run. They have many different degree programs that give you a little more choice when picking what scientific area or discipline you wish to enter. http://www.ubc.ca/