The Mushroom Kingdom

Downloads and information. Covers all Mario games and cameos, offers tips, and features the Mariopedia.
http://www.classicgaming.com/tmk/

Super Mario Bros. Headquarters

Reviews, polls, cartoons, guides, lists, and information.
http://www.smbhq.com/

Mario World

Provides information, downloads, and animations.
http://www.angelfire.com/bc/blueboy/mariostart.html

The Luigi Awareness Society

Dedicated Luigi. Includes pictures, information, and chat.
http://soulrain.tripod.com/LAS/

Yoshi's House

Contains wallpapers, fonts, images, and information about the character Yoshi.
http://www.angelfire.com/dragon/yoshishouse/home.html

The Home of Mario

Game help, guides, codes, Q and A, and reviews. Online arcade and forums.
http://maxpages.com/homeofmario

Neglected Mario Characters

Includes information on the more "neglected" characters of the series.
http://www.smbhq.com/users/nc/mario.html

The Luigi Network

Offers fan art and links.
http://www.geocities.com/jrluigi1988/

The Mushroom Kingdom

Offers pictures, music, fan art, fan fiction, desktop themes, and links.
http://tmksd.tripod.com/

Toad Kinopio

Offers information, sounds, and pictures about the Kinopio character.
http://hemsidor.torget.se/users/k/kinopio/

Mario Nostalgia

Images and screenshots from various Mario games and home of the Mario Game Graphics Webring.
http://mnm.ionichost.com/

SMBFan

Contains information, and screenshots.
http://smbfan.silius.net/

Super Mario Portal

Contains art, fan works, game information, editorial articles, ringtones, wallpapers, and an encyclopedia.
http://www.marioportal.com/

Mario Guide

Reviews, previews, articles, a chatroom, and viewer submissions.
http://www.marioguide.com/

Crazy 4 Yoshis

Contains pictures, music, forums, and a biography of Yoshi.
http://www.geocities.com/crazy4yoshis/

Super Mario Bros. Monster Compendium

Collection of data on the enemies that Mario and Luigi face in their adventures. Includes sample monster, monster archives, and gender equality sections.
http://www.mariomonsters.com/

Totally Mario

Contains storylines, cheats, and screenshots for various games.
http://www.totallymario.com/

The Quest for the Fastest Mario Time

An essay on the strategies, background, theories for Super Mario Brothers 1.
http://chronomario.tripod.com/

Super Mario 128 Central

Covers reviews and more on current generation Mario games.
http://www.sm128c.com/

Lovely Peach

Dedicated to Princess Peach Toadstool.
http://www20.brinkster.com/princesspeach/

Bigmouths Fort

Covering the Koopa Kids and the Mario series, especially "Bigmouth" (Morton Koopa, Jr.)
http://www.geocities.com/hoot5000/bigmouthsfort.html

Yoshiart.com

Features fan art, pictures, animated GIFs, and videos. Includes a forum and wallpaper section.
http://yoshi.2yr.net/

Yoshi Fan Club

Fan club with images and message boards.
http://groups.msn.com/YoshiFanClub/_homepage.msnw?pgmarket=en-us

Toad Town

Dedicated to images and information on Toad.
http://www.geocities.com/toadstown/

The Mushroom Kingdom: The Next Level

Mario fan fiction stories.
http://members.fortunecity.com/q2u/index.htm

DillMozza Inc.

Provides news, comics, sprites, artwork, links, and a message board.
http://www.geocities.com/dillmozza_inc/