According to the U.S. Department of State Terrorist Organizations list:

Follow up:

Abu Nidal Organization (ANO)
Abu Sayyaf Group (ASG)
Al-Aqsa Martyrs Brigade
Ansar al-Sunna (AS)
Armed Islamic Group (GIA)
Asbat al-Ansar
Aum Shinrikyo (Aum)
Basque Fatherland and Liberty (ETA)
Communist Party of Philippines/New People's Army (CPP/NPA)
Continuity Irish Republican Army (CIRA)
Gama'a al-Islamiyya (IG)
HAMAS
Harakat ul-Mujahedin (HUM)
Hizballah
Islamic Jihad Union (IJU)
Islamic Movement of Uzbekistan (IMU)
Jaish-e-Mohammed (JEM)
Jemaah Islamiya Organization (JI)
Al-Jihad (AJ)
Kahane Chai (Kach)
Kongra-Gel (KGK/PKK)
Lashkar e-Tayyiba (LT)
Lashkar i Jhangvi (LJ)
Liberation Tigers of Tamil Eelam (LTTE)
Libyan Islamic Fighting Group (LIFG)
Moroccan Islamic Combatant Group (GICM)
Mujahedin-e Khalq Organization (MEK)
National Liberation Army (ELN)
Palestine Liberation Front (PLF)
Palestinian Islamic Jihad (PIJ)
Popular Front for the Liberation of Palestine (PFLP)
Popular Front for the Liberation of Palestine-General Command (PFLP-GC)
Al-Qaida (AQ)
Al-Qaida in Iraq (AQI)
Al-Qaida in the Islamic Maghreb (AQIM) [Formerly Salafist Group for Call and Combat (GSPC)]
Real IRA (RIRA)
Revolutionary Armed Forces of Colombia (FARC)
Revolutionary Nuclei (RN)
Revolutionary Organization 17 November
Revolutionary People's Liberation Party/Front (DHKP/C)
Shining Path (SL)
United Self-Defense Forces of Colombia (AUC)

Details regarding each group's description, activities, strength, location and funding can be viewed HERE, although it doesn't look like it's been updated since April of 2007. A more detailed report can be found at this page on The Department of Treasury SPECIALLY DESIGNATED NATIONALS AND BLOCKED PERSONS page.

Kahane supporters: Please don't contact me about Rabbi Meir Kahane (tz"l) being on this list, I didn't create it and don't agree. If I were to strike his name from the list I wouldn't be accurately reporting what's in the file.