I agree with Darieth, DBM and Omen (or similar) are a must have for raiding, everything else is personal choice.
Recount - not so I can see who is top DPS but for deaths, healing etc, I do use the DPS meters but as a raid leader (are we pulling enough etc) rather than for personal use
That's all I use at the moment. I used to us raid buff status but I haven't reinstalled it since the patch...I will one day soon and catch certain Team Awesome members out. I have issues with my PC though so the less I have running the better!
Different guilds/teams use different add ons so you should always ask first (some use loot add ons etc), but DBM and Omen are the only must haves for a PCG raid.