What are the best undergraduate colleges for science in general?

There are a lot of them. Most very good universities are very good at sciences, and there are hundreds of very good universities and colleges. Some schools that are strong at many sciences are not as strong at engineering.

Perhaps one way to start the discussion is to tell us your GPA (unweighted is usually more useful because weighted GPA is computed so differently in different schools), SAT or ACT scores if you have them, home state, financial situation (what you can afford), and what you want in a university (big, small, rural, city, northeast, southwest, football, hockey, …).