The big generic sites

• All-Music Guide (graphics frequently crashes operating system)
• Iceberg
• Encyclopedia of Popular Music (excellent)
• Music.com
• iMusic archive of bands
• Internet Underground Music Archive
• Rock's Backpages (an online library of rock & roll)
• Rockmine
• Rolling Stone
• Rough Guide
• Piero Scaruffi
• Starpulse
• Trouser Press (excellent)
• Ectophile
• Metacritic (list of reviews)
• iq451 (list of reviews)

Meta-archives (archives of links)

• Sonic Boom
• UBL
• Snap
• Open Directory Project
• Pug's Linkage
• Yahoo
• Electron Music - a huge catalog of links organized by genre
• Eternity Rock - a music search engine
• Directory of fanclubs

Discographies

• Discog - discographies
• Grunner Rock - indie music
• Discography Central
• Tweenet
• Soft Shoe - album lists
• Rock list - music discographies
• Pretentious archives of discographies
• Lazlo Nibble's Discography Machine
• Q Magazine's discographies
• Impossible Discographies
• Rock discography
• Rubin's rock and roll discography
• Southern Studios database of bands
• Sort Music

Jazz discographies

• Black Saint
• Soul Note

Rock Genres

• Space Age Pop
• Reason to Rock - a site on rock music as an art form
• Outer Side - database of recording studios
• History of Rock Music - Rock and Roll's golden decade
• Sixties Web - A database of pages on classic rock and bibliographies
• Bubblegum music
• CAKE!-the non-music music zine - A database of grunge bands
• Harmony Ridge - a database of female singer songwriters
• Psyche Van Het Folk - a database of progressive folk around the world
• Piero Scaruffi's History of Rock Music

Lyrics

• International Lyrics Server - searchable index of over 100,000 songs
• Lyric Connection
• Lyrics Time
• Lyricx
• Dark Phoenix
• Ken Reamer's lyric site
• Lyrics.duble
• Search engine for lyrics
• Search engine for lyrics
• A lyric

Sounds/ Download services

• MP3fiesta - this is the one i'm using in 2009 ($45 for unlimited downloads for one year)
• Musicmp3
• Gomusic
• E-music
• Beware of websites that advertise "unlimited free downloads" and proclaim that the above are scams: the "unlimited free" services have virtually no selections but will harvest your email address and sell it to spammers

Videoclips

• Live Music Channel

Tours

• Deterrent DIY Tour Guide
• Indie Music's Tour Guide
• Musician's Assistance Site
• Pollstar
• Gigmania

News

• MTV news
• iMusic news
• Spin news
• Alternative Press news
• Fresh Music Farm
• San Francisco nightlife

National and regional Scenes

• Gnosis, national scenes
• German rock discography 1963-79
• German rock encyclopedia
• JAM Encyclopedia of Canadian bands
• A database of Austrian rock
• A database of Japanese rock
• A database of Uzbekistan rock
• Argentinian rock
• Japanese underground
• Canadian indie bands
• A database of Australian discographies
• New Zealand popular music
• Florida bands
• Boston Rock archives
• San Diego rock
• Washington DC rock

Country Music

• CMT

World Music

• International Library of African Music
• Global Music
• Ethnomusicology Online Home Site

New Age And Electronic Music

Dance music

• Electronic Dance Music
• Disco music
• Deep Disco
• Disco Disco
• Larry Levan's website
• Dance artist info
• D.J. Rhythms dance music database
• Global Trance and Dance
• German techno artists
• Acid Jazz server
• Techno discographies
• Techno.org
• Dance music resource pages

Heavy metal

• Chedsey.com - independent reviews of heavy metal, punk-rock, industrial
• Metal Index
• Metal Storm
• BNR
• Grave
• Doom, thrash and death metal links
• Metal Desert
• Stoner Rock
• Heavy metal reviews
• Tangento metal & punk

Punk-rock

• Hiljaiset Levyt's Punknet 77
• World Wide Punk - (bands, labels, zines)
• Punkmusic - (bands, zines, labels)
• FLEX discography of US punk & hardcore
• Punkrocks.net - (bands, reviews)
• Be Stiff
• Kontrol
• Swiss Punk & Wave
• punkrock.org
• Punk77

Industrial/Gothic

• Brainwashed database
• A Bullet Hole in the Face of Reality
• Ed's music database - a historical landmark on the web
• NightCrawler Gothic Search Engine
• Sublevel 203
• Archive of links to industrial music bands
• Links to goth culture
• Official Goth homepage
• Gothic Music
• Carpe Mortem
• Chicago Gothic
• Darkpark
• Detroit Gothic
• Digital Underground
• Eclipse Industrial Server
• Evosonic Radio
• German Gothic.NET
• Goa.DE
• Goth classics
• Goth.NET
• Gothic Handbook
• Gothic.NET
• Gothgurl
• Industrial Nation
• Industrial Page
• Infrarot Mailorder
• Isolation Tank
• Kybernaut
• Martz Mailorder
• Miningco links
• Netzwerk Radio Darmstadt
• Phuture.COM
• Radio Distortion
• Radio Future II
• Requiem
• Rivet Head repository
• So schwarz ist Köln
• Subnation
• Switchboard
• Taste of New Roses
• Top sample list
• Piero Scaruffi's History of Rock Music
• Twilight Pool
• Xtra Undergroundfashion
• Zillo links

Dub/reggae

• An archive of reggae links
• The list of reggae albums
• A discography of dub albums

Psychedelic

• Delerium's Psychedelic Web - Huge A-Z of psychedelic music
• pOoTers pSycheDelic shAcK
• Borderline's encyclopedia of psychedelia
• Haight-Ashbury library
• Texas psychedelic rock
• Psychedelic Music Net

Soundtracks

• Colonne Sonore (in Italian)