Props to Eloquence for the idea. See also this explanation of how they work.

http://en.wikipedia.org/w/wiki.phtml?title=%s&redirect=no
Avoids redirection. Most useful for viewing pages that redirect to other wikis.

http://en.wikipedia.org/wiki/Special:Whatlinkshere/%s

What links to a given page.

http://en.wikipedia.org/wiki/Special:Contributions/%s
Shortcut to a user's contributions.

http://en.wikipedia.org/wiki/%s
Go directly to a page.

http://fr.wikipedia.org/wiki/%s
Go directly to a page on 
fr: (or any other language; substitute the two-letter language code
as desired.

http://en.wikipedia.org/w/wiki.phtml?title=%s&action=history
Shortcut to the history of a page.

http://en.wikipedia.org/wiki/Special:Undelete/%s
Undelete a page (sysops only).

http://en.wikipedia.org/w/wiki.phtml?title=Special:Blockip&ip=%s
Block an IP or username (sysops only).

http://en.wikipedia.org/w/wiki.phtml?title=%s&action=delete
Delete a page (sysops only).