For what? If you're not sure what you want to do, go for a decent state university where tuition won't put you under a mountain of debt. Your best bet will be a well rounded university that has a decent program in everything from chemistry to fine arts to sociology, but may not be in the top 10 schools in any one area. If you know what you want to do (and I've changed my mind 20 times since I was 14), then you can look for schools that are more highly ranked in the programs you want to focus on. The problem there is if their focus is too narrow, if you decide to change majors you may not have as many options as you would at a more rounded university.
It definately depends on what you want to do with your life. A lot of universities have tons of programs to choose from. Snoop around a bit....
