Easiest/Funnest Set up to DUAL box

[Ualaa]

Kind of tongue-in-cheek, but it will be fastest to realize 5 > 2.
A lot more fun combinations to try with 5.

For a long time, I ran: Priest/Mage, Druid(Dreamstate)/Warlock(Affliction) and Priest/Rogue.

[lans83]

Disc Priest + Hunter works out. I use my DP with 3 Hunters in tow, 2xBMs and 1xMM. I've cleared alot of dungeons at and around level for them, but haven't made it out of Outland yet. I box 4, but that duo is a good one too. You've got a dedicated healer, dps, and simi-tank. Same principal with a DP+Lock, or DK + Dp in tow healing. Pally tank and Priest healer might work out too.

[Mooni]

In the old days (TBC) I did a prot warrior and resto shaman 1-70 together.
This was not the most fun.
If I ever did a "practical" group like that again, I'd change the tank to a druid for the extra buffs and stuff.

Sorry, whenever I think of "funnest" it ends up turning into logical or pragmatic. So what's the funnest?

For me that'd be hunter/warlock. 4boxing for the cost of 2boxing!