Gallup conducts research on the attitudes and behaviors of employees, customers, students, and citizens. They publish books and reports on various attitudes and behaviors of people worldwide.
Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping the world. The Center conducts public opinion polling, demographic research, content analysis and other data-driven social science research.
The Roper Center holds polling data ranging from the 1930s, when survey research was in its infancy, to the present. Almost 700,000 questions of U.S. samples can be searched at the question-level in iPOLL, while RoperExpress offers downloads of 23,000 datasets from over 100 countries.
YouGov is a global public opinion and data company. YouGov Ratings continually measures the popularity of everything from pop stars to politicians, sports teams to snack foods, and almost anything in between.