I've recently begun using this handy little piece of software for viewing PDF documents.
I use a lot of different texts for a course of study that I'm undertaking and PDF-XChange Viewer is excellent. This is mainly due to the tabbed interface, which means that I can have many PDF files open at one time and easily change between them as and when required. This is a small, yet welcome advantage over more traditional readers like Adobe Reader.
There are the usual PDF reader features like page rotate, snapshot, text & object select & document search, etc., etc. It does it all.
I'm actually running the portable version which is handy to run off a USB drive while using work computers, etc.
The best part? It's FREE!
Check it out HERE.