Nearly 2,000 16 to 19-year-olds answered questions on the Science Year and Science Museum websites on curriculum content.
Three-quarters of students wanted more real-life, practical examples. More than half felt that GCSE science tested memory more than understanding.
Smaller classes, more emphasis on the moral and ethical implications of science, and dissection in biology would all improve lessons, according to the teenagers.
Science experiments in schools have been cut back because of fear of legal action and a shortage of lab technicians. Concerns about animal rights and pupil sensitivities have led to a decline in the number of dissections.
The Government's exam watchdog is developing a hybrid science GCSE which will be made up of a compulsory core, followed by academic or vocational options. The Qualifications and Curriculum Authority also plans to include more investigation questions in the national curriculum tests.
Schools minister Catherine Ashton said: "This poll has come at a time when we are exploring an innovative structure for GCSE science that will engage pupils in contemporary scientific issues."