Good 5 man comps purely for pve / dungeon leveling

[CokeZero]

Thanks for the suggestions. I've narrowed my choices to these two:
warrior / priest / 3 mages
paladin / priest 3 mages
(warlock would probably be great as well but I want 3 different classes at most to keep it simple)

How do they compare?

I run a bear tank, priest, warlock, and 2 mages. Mainly because I wanted to provide my team with every available buff

Mages, as far as DPS goes in a multiboxing setup, are far superior in almost every way. The AoE control is just so damn good and they don't go OOM in seconds like a warlock does. Warlocks you need to weave in a lifetap here and there to keep them casting.

That said, I do not regret putting a warlock in the team, and if I had to level a new team all over again a warlock would be a must for me. I love the utility they bring with healthstones, soulstones, more HP if you're running a tank with imp stamina, and if you're running a warrior tank the imp fire shield can help the tank hold aoe threat. The fire shield is useful on the bear as well when you are fighting nature immune mobs, since thorns is nature damage. I guess it's useful for a pally too, not sure if it stacks with whatever they may have, dunno, never played one.

And then of course the main reason I love my warlock, summoning! I love being able to ship a toon back to town to empty bags and sell, then summon him right back and keep on grinding/farming.

[Mordikai]

I have been working on an Alliance team now (novel for me, I always play Horde) and went PaPMML and I have to agree, I will always have one. The Warlock brings so much to the table. I exclusively am using the imp. I am specced full destruction right now so the mana is not as bad and I tap on the run with renews from the Priest to help keep up the pace. The Paladin has fire shield, retribution aura, blessing of sanctuary and a shield spike. He is a total reflect machine! I have a castsequence rotation that if the fight goes a little long he casts drain soul to keep the shards up so I always have health and soul stones. Curse of the Elements really helps the mage's damage as well. The best part though: Staying at dungeons for ever, sending the mages back to sell and then just summoning them back

[nodoze]

I have been working on an Alliance team now (novel for me, I always play Horde) and went PaPMML and I have to agree, I will always have one. The Warlock brings so much to the table. I exclusively am using the imp. I am specced full destruction right now so the mana is not as bad and I tap on the run with renews from the Priest to help keep up the pace. The Paladin has fire shield, retribution aura, blessing of sanctuary and a shield spike. He is a total reflect machine! I have a castsequence rotation that if the fight goes a little long he casts drain soul to keep the shards up so I always have health and soul stones. Curse of the Elements really helps the mage's damage as well. The best part though: Staying at dungeons for ever, sending the mages back to sell and then just summoning them back

I also really like my Warlock with my Paladin Tank and take the improved imp talents for the improved blood pact stamina boost and reflect damage from improved Fire Shield.

Regarding Soul Shards I like the SoulSort addon as it allows me to keep them topped off without filling my bags.