Never have liked Acrobat reader. It’s slow, clunky, bloated, and prompts me to install lots of other Adobe stuff I have absolutely no interest in whatsoever randomly when viewing PDF documents.
Get Foxit. It’s just over 1mb to download, and consists of only one executable – no installation required.
Update: Unfortunately, I’ve found that some PDF documents cause Foxit to throw an error, but work fine in Acrobat Reader, so I’ve had to reinstall it, though it’s not my viewer of choice. Bummer. Would’ve been nice to be able to get rid of it altogether.
Update: Mark pointed out that deleting the contents of the plug_ins folder can drastically speed up Acrobat. I’ve done this and it does really make Acrobate lightning fast. Thanks for the tip!