Depends on who is more mutable, the druid or the warrior. druid/enc, druid/wizard, warrior/cleric, warrior/sham

id prefer a shaman / ench to a druid / ench. Sure the druid can snare the pet but so what? that charms going to last MUCH longer when debuffed by a shaman.

The druid/enc duo is about fear kiting.

Can fear kite with a shaman as well if you pick the right race on the sham :) Dont really need to fear kite with sham / ench though, you just wreck everything.

Druid lacks the healing of a cleric to keep up with a warrior's HP, but SoW, ports, and DS would balance that, I think. Not a bad duo by any means.

Druid/warrior is extremely viable for agro kiting (make sure warrior is Zerked for maximum results).

Druid/enchanter is an incredibly powerful outdoor combo because of snare and heals. The argument can be made for shaman but that would better suit indoor dungeons. Heals cost tons of mana outside of CH and Torpor - anytime you can take advantage of levelling without taking damage you'll level the fastest.

Honestly, play whichever you enjoy with your friend.

For longevity I'd recommend Warrior/Cleric for shear access to high end groupage instantly when in the 40s+