While getting document viewers deployed onto Japanese handsets I’ve consequently mucked around with more than my fair share of PDF utilities over the last three or four years. Sumatra has got to be the best one I’ve come across. Simple and lickity-split fast.
Now if it just wouldn’t crash on Japanese documents.
If you have PDFs on which Sumatra crashes, please do open bugs (http://code.google.com/p/sumatrapdf/issues/list) and attach those PDFs to the bug.
(I’m the author of Sumatra).