This is a much deeper subject than even I realized just a short time ago.
I will give you the short version and it meets all of your needs specified as long as your pdf's are publicly accessible via http. This did not meet all of our needs but I hope it helps you.
Partial Solution
Not all browsers support this but some browsers support pdf as the source of embed, object and iframe tags and even allows you to view them without added javascript.
<embed src="file1.pdf" width="500" height="650"></embed>
<object type="application/pdf" data="file1.pdf" width="500" height="650" ></object>
<iframe src="PDFDirectory/Test.pdf"></iframe>
Answer
To get them to work in all browsers, rasterization and either JS or Flash is the answer. Surprisingly even google presents their pdf's in their viewer as a series of rasterized images. The good news is that you don't have to manually convert them and keep up with them if you take advantage of Google's publicly available viewer. Let google do all the hard work for you and save yourself from the frustration of GhostScript and ImageMagick (which is what we ended up having to use)! All you have to do is paste the url to your pdf and get the embed code! Not to mention that it was easy to programmatically generate the respected code.
https://docs.google.com/viewer