These are the minimum addons that we require for raiding:
-Deadly Boss Mods
-Omen Threat Meter
-ORA2 (Lightweight version of CTRA)
-EPGP (take the release version and _not_ the beta) (optional)
Other addons might be added later on and some might be removed as blizzard impliment them as features in the game.
EDIT: Changed the URL for ORA2 since it was outdate, Xath 29/01/2009