A necro is a solid choice if you are looking to solo and group. Although there are now npc warriors and clerics (mercenaries for hire in PoK) in the game that can make any class viable alone if you can not find a group.
A mage is also a good choice for a caster type. You get a good pet but the safety net of feign death isn't there.
If you prefer to try a more 'invasive' class you might want to try a beastlord.
If you are willing to learn to kite a druid is a great choice.
You might need to 'waste' a little time and level a few toons up to see if they are what you hope for or not.