There are so many reasons I hate Acrobat Reader, so this post is really one of many, but… if you install Acrobat Reader, you are required to use it to view PDFs in Safari. It used to be that you could disable this “feature”, but in recent versions of Reader, this has happened:

There is no way to uncheck that box. Thanks, Adobe. I’d really prefer to use the PDF viewer built into the browser, and not nuke your plugin every time Acrobat Reader gets a security update.