Free forum : Well it's a mix of anything and everything from a anime, gaming, music and socialising website.
+anime, +forums, +game, +kingdom, +hearts, +final, +fantasy, +teen

The Official Forum of Samar Underground - The Point of Convergence of the Samarnon Friendship
+about, +samar, +calbayog, +tacloban, +catbalogan, +music, +waray, +sector, +friendship

RuneScape Underground. Talk about Runescape private servers. Sell Runescape accounts. Do whatever you want that has to deal with runescape.
+free, +forum, +funkynater, +funky, +nater, +naterscape, +funkscape, +runescape, +hullana, +dodian, +hellhounderz, +phailscape, +lggl66

The Underground
+forum, +labyrinth, +jareth

Ran Underground Philippines
+private, +server, +philippines

Welcome to the Sports Talk Underground Network Community Forum.
+football, +sports, +talk, +peyton, +manning, +bears, +colts, +national, +league, +eagles, +cardinals, +patriots, +cowboys

Suikoden Underground Forum- Discuss the greatness of Suikoden
+suikoden

The Underground Network
+network

For those of us who'd rather have something to do...
+free, +forum, +freeman

Presented By Dj Excess, Mc Bouncin & The Spanish Underground Team
+excess, +spanish, +bouncin, +ruption, +monkey, +rave, +northern, +rave, +ultimate, +buzz, +dimensional

Free forum : Welcome to RCU.A new place for cheaters, programer, coder and trainer maker!~this is currently under customisation.but please enjoy here
+free, +forum, +reaper12, +renegade, +cheaters, +darkogg

The #1 place to discuss underground hiphop, and hiphop at it's finest.
+free, +forum, +pure, +good, +hip-hop

Programing language
+programing, +language

For the underground heroes. I salute you.
+heroes, +salute, +you.

Ohio Underground Street Racing
+ousr, +ohio, +forum

Saint Louis underground Music Discussion
+saint, +louis, +music, +discussion

DARKPSY, underground trance forum from portugal.
+psytwist, +darkpsy, +trance, +forum, +from, +portugal.

Free forum : modding
+modding, +windows, +skins, +itunes, +icons, +wallpapers, +anime, +windowblinds, +visual, +styles

Cyberfluo Chaos!
+punish, +yourself, +punk, +cyberpunk, +indus, +fluo

Strategy guides and helpful information for clan members only!
+free, +forum

Best Board On The Web!!!
+best, +board, +web!!!

Forum for Magic Philippines
+close, +magic, +mentalism, +street, +philippines, +distortion, +fusion

Extreme underground Wrestling
+extreme, +undrerground, +wrestling, +foremole, +thewrestlinggame

Home of Pinoy Digital DJs
+bcd2000, +bcd3000, +xponent, +connectiv, +hercules, +console, +vestax, +vci-100, +trance, +house, +turntablism, +disco, +chill, +bedroom, +breakbeat, +techno, +reggae, +drum

Welcome to the Survivors Forum[Underground]
+proud, +survivors