Monk:
Must haves: Rapid Feign, Imitate Death, Hastened Death, Run speed, Weightless Steps. Make sure to have the disc Impenetrable (lvl 72). (Yes, you can survive Death Touches with it.)
Nice to haves: CS/CA, Technique of Master Wu, Punch Mastery, Kick Mastery, Rapid Strikes (Monk Flurry attacks), Veteran's Wrath, Combat Fury, Burst of Power, Ferocity, Weapon Affinity.

Lots of others but those stick out as above average for return on AA's invested.

Magician:
Must haves: PET DISCIPLINE first and foremost! Pet Discipline = Pet hold. No pet hold, no pet! (And what's a mage without a pet...hint: wizard without mana), run speed, elemental alacrity, frenzied burnout.
Nice to haves: Host of Elements (swarm pets), Servant of Ro, summoner's beckon (50% chance to not use reagent when using CotH), The entire line (up to your level) of Gift of mana line of aa's.

Can't stress the need for pet discipline enough....you can't have a pet during a raid without it.

Wizard:
Must haves: Run Speed, Spell Casting Fury, Spell Casting Fury Mastery, Spell Casting Subtlety, Spell Casting Subtlety Mastery, Spell Casting Mastery, Innate Enlightenment, Silent Casting, Destructive Fury

Nice to haves: The entire line (up to your level) of Gift of mana line of aa's, Mana Burn line (again up to your level), Twincast.

Shaman:
Must haves: Run speed....not sure what else....Rootts? Where are you?


Undoubtedly others can refine my lists. (Just found out recently my monk is considered a defensive monk, not dps...oops.) Generally speaking, a caster will benefit from the Gift of Mana line substantially if used properly. Spell Casting Mastery (base percent reduction in mana cost) is also a safe bet. Also, don't forget your Mnemonic Retention AA. Those extra 2 spell gem slots come in handy.


-Kik

There are a lot of places that go without saying but heres the input I can give (never have played a tank so I am just going with the obvious-wait on Queen/Tapout etc to add to this post.)


Casters: MGB, Quickened MGB(that lowers the timer between mgb popping up, Pet hold, Casting Subtlty and class specific aas ie

improved healing, RGC etc for healers.

Enc- Mez mastery, charm mastery(don't recall the name but the one that makes them less likely to break charm early), Beguilers Directed Banishment.

tanks: obviously max out your agility because it adds to your ac, max out your mitigation, and all your defensive/offensive aas...I have no clue on the class specifics there though lol.