Good 5 man comps purely for pve / dungeon leveling

[zehedas]

You mentioned dungeon grinding and not raiding. This might not be common thought but you need a hunter in the mix.

Hunters are top notch dps pre-raid, just fall behind when you start getting geared up.
An owl pet with level 4 schreech is amazing AOE threat. When you lose a mob it turns to the pet not the healer or mages. No chasing it.
Easier gearing as its the only mail wearer if no shaman, easier gearing your clothies as well.
Pair with engineering and feign death gives you one less chance to have to run back from the graveyard after a wipe.

How do you deal with the dead zone when multiboxing hunters in a mixed melee-ranged group?

5 hunters or shamans (or shamans+hunters) sounds like it could be fun, too. Does anyone have experience with groups like that?