Super Smash Bros. Fantasy World

Includes storyline, tips, cheats, and secrets, stages, reviews, techniques, character and level guides, music and screenshots, forums, and chat.
http://www.smashworld.org/

Smash HQ

Containing information, downloads, and secrets.
http://www.geocities.com/spyroo6/index.html

Super Smash Bros. RPG

A forum based roleplaying game for the series.
http://pub79.ezboard.com/bsupersmashbrothersrpg78503

Video Game Nutz

Offers screenshots and cheats for the series.
http://www.vgnutz.com/fighting/super-smash-brothers-series.htm

Super Smash Bros. Arena

Includes news, forums, polls, contests, media, character profiles, reviews, walkthroughs, records, and rumors.
http://dynamic5.gamespy.com/~supersmashbrothers/