I use PDF to go. I have a full version of Documents to Go. It will read multiple pages of PDF's. Doesn't always work, but I like it much better than the BB native application.
I have Docs to Go Premium (paid), which has a nice PDF viewer. There is also Native PDF Reader for BlackBerry and Repligo (for which I don't have a link).
Posted from my CrackBerry at wapforums.crackberry.com