Foxit PDF Reader
In the early days, Adobe Acrbat Reader was a great tool for reading PDF files. But in the past months, it has transformed into a slow-starting, update hungry irritating tool which pops up questions about upgrading parts of the program you didn't even request to be installed. If you have the older version of Acrobat Reader without the update manager, hang on to it.
If you are looking for a nice alternative for Acrobat Reader, I can recommend Foxit PDF Reader. It is a very small program, free, and starts up in about 1/10th of the time Acrobat Reader takes to display just the splash screen (and subsequently, the annoying update manager). It can do anything I usually need when reading and printing PDF files, and the fullscreen mode is even richer than Adobe's.
Adobe seems to have gone overboard with their userinterface. People just want to read the PDF, and not be bothered with complicated questions which very often result in downloading and installing megabytes of unwanted software on their machines. I will recommend alternatives to Acrobat Reader from now on, and I think the world will become a slightly better place ;-)