• WP:WP (all shortcuts)
• WP:AFD (articles for deletion)
• WP:AIV (admin intervention for vandalism)
• WP:AN (admin noticeboard)
• WP:CITET (citation templates)
• WP:CLEANUP (cleanup)
• WP:EIS (extended image syntax)
• WP:HTUT (how to use tables)
• WP:MM (merging)
• WP:PROD (propose for deletion)
• WP:REDIRECT (redirect info)
• WP:RFPP (requests for page protection)
• WP:SAND (sandbox)
• WP:SPAM (templates for spam warnings)
• WP:VANDAL (templates for vandalism warnings)
• WP:WM (maintainence)

Others:

• Wikipedia:As of ([[As of yyyy]] for 2000+ can use [[As of (month) (year)]])
• Wikipedia:Template messages/User talk namespace (various warnings)
• Wikipedia:Categorical index (categories grouped by topic)
• Category:categories ({{uncategorized}})
• Category:Stub categories ({{stub}})
• {{wikt:word}} to make little box with link to Wiktionary
• [[wikt:dictionary|dictionary]] makes dictionary that links to Wiktionary
• [[w:article:article]] to link to Wikipedia from Wiktionary

Formatting:

• <del> (strikethrough)
• <s> (strikethrough)
• <sub> (subscript)
• <sup> (superscript)
• <small> (small print)

Foreign language:

• Category: Wikipedia multilingual support templates
  • {{lang-pt|word}} makes: Portuguese: avinho
  • {{lang-ja|word}} makes: Japanese: sushi
  • {{zh|word}} makes: Chinese: Qi Xi
• Template:Nihongo
  • {{nihongo|English|Kanji|Romaji|inside|outside}} makes:

English (Kanji, Romaji, inside) outside

Miscellaneous:

• <!-- comment here -->
• <ref name="cite"> (this will name a citation so that it can be used later)
• <ref name="cite"/> (this will insert a link to the previously named citation, </ref> not needed)
• {{fact}} (will print "citation needed")
• {{MultiCol}} {{ColBreak}} {{EndMultiCol}} (for making multiple columns)
• {{imdb title|id=0110169|title=It's Pat}} makes: It's Pat at IMDb
• {{bibleverse||Acts|10:22}} makes: Acts 10:22
• {{bibleverse-nb||Acts|10:22}} makes: 10:22