I have nicked this lot of RAWK they have a similar thread. Hope they don't mind.
General
Xtra Time An extremely busy set of forums covering every club, league or country you can name.
Arsenal
Arsenal Mania
Arsenal Land
Gunnershigh.com
ArsewebThe oldest of the Arsenal fansites, offers news and stats but no forums.
Arsenal News Review - This is a great site written by two Arsenal supporters. Myles Palmer is an astute observer of football, mainly Arsenal but also on other teams and players/ Ian Grant covers Arsenal in the news. No forum but well worth a visit for Palmer's thoughts.
Goonersweb - Goonersweb is a lively online community for discussion about Arsenal FC, other football news and has sections where users can chat about other topics. Away fans welcomed.
Aston Villa
Heroes & Villains
VillaTalk
AVFC Blog - Aston Villa news and opinion with forum and comments.
AVillafan
Chelsea
CFC-Net The leading independent Chelsea fan site with news, player interviews and lively discussion boards. Some of Rawks finest can occasionally be seen here. They've currently filled their quota of resident Liverpool supporters though so...
Chelsea Mad
Crystal Palace
Holmsdale Online
Everton
ToffeeWeb - Excellent site offering news and comment on all things Evertonian. There's a forum attached to the site but the People's Forum is a busier and funnier alternative.
The People's Forum - Long established Everton supporters forum. Some great banter and easily the pick of the Blue fora.
BlueKipper - Irreverent site with News, comments from Micky Blue Eyes and others and some naughty digs at their superior neighbours. Forgive them, they know not what they do.
Love Everton
http://www.loveevertonforum.com/forum - kindly mentioned Rawk on their site, pay them a friendly visit
Fulham
FulhamFC Messageboard
Fulham Rivals - There's Only One F in Fulham, Fulham section of the popular 'Rivals' Network.
FulhamWeb
The Green Pole
Fulham Supporters Club
Hull City FC
Hull City - Official site
Amber Nectar
Hull City Mad - Hull part of the Footymad site
Liverpool
For other Liverpool fansites see the
LFC Fansite Guide
Manchester City
Blue View
Blue Moon
Manchester United
Red Issue - prepare to be called some nasty names
United We Stand
Red Cafe
Newcastle United
Toonchat
Newcastle Online - a very polished site with popular forums.
Toontastic - another good magpie site.
NUFC
True Faith - Fanzine website
Southampton
SaintsForever
TheSaintsForum.co.uk
http://www.saintsweb.co.uk/forum.php
Stoke City
The Oatcake
Why Delilah
Delilahs
Sunderland
A Love Supreme
Tottenham Hotspur
Glory Glory
Spurs Community
THFC Talk
West Bromwich Albion
West Bromwich Albion Mad
Baggies.Com
West Ham United
KUMB.com - Knees up Mother Brown, a good Hammers site.
West Ham Online
Birmingham City
Birmingham Sporting Network
Singing the Blues
VBB Football - Villa Blues Baggies - combined Midlands footy
BluesMuse
Blackburn Rovers
BRCFS.co.uk
Rovers Talk
Bolton Wanderers
Bolton Banter
The Wanderer Excellent fan site with busy forums. Running a campaign to knight Nat Lofthouse which deserves wider support.
BWFC4U.comWanderersways
Charlton Athletic
Addicks Online
CAFC-Fans.co.uk
Charlton Blogspot
Derby County
The Rams
Leeds United
To Ell and Back
LeedsFans.org
Luton Town
LutonFC.Com
Middlesbrough
Fly me to the Moon
Come on Boro - Best of the Boro sites imo.
Borobarmy
Boro rules
Portsmouth
Portsmouth Rivals
Reading
Royals.org aka as Hob Knob Anyone?
Scunthorpe United
Irn Bru
Sheffield United
Redandwhitewizards
Unitedite
On the Kop
Watford
The Golden Boys
Glory Horns
The Darkside
Wigan Athletic
Ultimate Wigan
Ye Olde Tree and Crown (YOTAC) a friendly Wigan site.
Cockney Latic
Belgium
Anderlecht
http://www.anderlecht-online.be/
http://www.rsca.be/
France
[
http://forum.girondins.com/index.php/]Bordeaux Girondins
Olympique Marseille (with an English forum)
Monaco
http://www.red-boys.net/
Germany
Bayer Leverkusen
http://www.fanclub-kunterbunt.de
www.werkself.de
www.1904-online.de
Borussia Munchengladbach
http://forum.borussia.de
Greece
Olympiakos
www.ultras.gr
www.gate7europe.com
Holland
PSV Eindhoven
http://www.psv.nl (Official Site)
Israel
Maccabi Haifa
Green Apes
Italy
AC Milan:
http://forum.acmilan-online.com
http://www.milanmania.com
http://www.devilsmania.com
Inter Milan:
http://www.forza-inter.com
http://www.interfans.org (this is their most popular forum, unfortunately the language is in italian)
Juventus:
http://www.juventuz.com
AS Roma:
AS Roma
http://forum.carlozampa.com/
Portugal
Benfica:
www.serbenfiquista.com
Spain
Deportivo La Coruna
http://www.deportivo-la-coruna.com
Turkey
Galatasaray
CimBomBom
Fenerbahce:
http://forum.antu.com (The forum is very big and busy, the language is turkish, but they had the english forum as well)
Scotland
Celtic:
http://www.thehuddleboard.com
http://www.celticminded.com
http://www.talkceltic.net
Rangers:
http://www.followfollow.com
http://www.scotzine.com