Foxit pdf Reader

Use – to read pdfs AND to annotate them
Cost – Free
Description:
The Foxit Reader is a small, fast, and feature rich PDF viewer which allows you to open, view, and print any PDF file. Unlike other free PDF readers, Foxit Reader also includes easy to use collaboration features like the ability to add annotations, fill out forms, and share information with social networks.
Developer: http://foxitsoftware.com/Secure_PDF_Reader