I run 3 teams, depending.

MT Raid Group:
Guard - great tanking ability, horrible aggro control against more than 1 target.
Defiler - part of the dynamic perfect healing duo for raid mt groups
Templar - the other part of that dynamic healing duo
Dirge - hate control and melee proc to help the guard keep aggro
Coercer - hate control, dps and pet-offtank
Warlock - AOE Dps
This team is designed to tank in a Raid and effectively cannot die (unless you forget to pre-ward/heal, or just plain mess up). One issue is Low DPS... w/ Epics & T1 Armor, you'll only be pulling ~ 7k dps (depending). You can walk into a Deep Forge or the first two Scion TSO Instance (unmentored) w/ Kunark gear and should be able to complete the daily mission. The rest of TSO is hit or miss. another issue is Aggro Control... Unless you're geared up and AA'd up, the Guard just cannot keep aggro on more than 1 mob effectively. YYMV, but if you want an AOE Tank, go Bezerker.

DPS Hunting Group
Shadowknight - Decent->Good Tank and Awesome Aggro Control
Warden - With this group, you need heals, not a dps healer (fury). Warden Mythical = Easy Mode Healing
Troubadour - You will need power regen and Aria (spell proc) absolutely rocks
Enchanter - Power Regen, Healing Buffs and single target DPS all in one package. Time Compression (drool)
Conjuror - Awesome AOE Dps (epic + t2 shard armor + aoe mobs = 4k+ dps), especially with a caster pet in a group with a troub and enchanter.
Wizard - pure unadulterated single target dps
I just got this team into Full T2 Shard armor w/ Epic Weapons yesterday. All of them have 187+ AA (3 guys @ 200 already). I love this group. If I'm slacking, I pull ~ 10k dps (using treasured/legendary kunark jewelry). If I focus on a fight i can pull 12k+. If I pull a couple AOE Groups, I can easily suprass 20k DPS (30s burst).

DPS Raid Group
Warlock , Warden, Troub, Enchanter, Conjuror, Wizard : Nuff Said

I love my DPS Hunting Group. It was a PITA growing them up. With one healer, I had no chance in any TSO Instance, even trash mobs wiped my group... I got them all into T2 Armor w/ Epics (150 grey 'daily missions' ugh) yesterday and cleared the first two Scion TSO Instances, Deep Forge & Najena's Hollow Tower (with 1 healer!!). I got to the end boss of Crucible, but I still have to work out some kinks in the book clicking thing every 20% (/sigh).

It really doesn't matter which class you pick, as long as you pick classes that compliment each other. Don't group a Dirge with a bunch of Casters... Don't run a Troub in a MT Group... Check out eq2wikia and read what spells do what for each class, then do your thing.

And yeah, in my MT group, I should have gone Swashbuckler or Assassin instead of teh Warlock... but I didn't wanna have to worry about mob positioning on every pull. Sometimes, Laziness Wins !