I'd go with shammy for the str/sta/dex/regen that the pets will benefit more from than heals (as well as slows plus shammy can tank/hold aggro with backstab pets whooping) but if you wish to be far lazier - cleric.
Lazy APM - SK, cleric, mage or wizard Lazy APM with beast - beast, cleric, mage. You'll see a pattern with mage + cleric. It's such a good combo for leveling. Cleric with CH and good HoT's and lull indoors. Mage with an OP pet. Add beast with slows, some tanking ability and later mana regen and you can do anything.
3 lizard monks. Pull on "new" monk every pull. FD to loose agro on low health one. Mend and bandages for heals. I did 3 rangers to 50 like this with almost no downtime. Come 50 find friends to group with and heal your ass or tank for you.
