It really depends on what you want to do. For sheer power, necro/necro or maybe necro/mage. For utility, I think it's hard to beat a druid. Dots, regen, sow, and ports are really a time saver pre-pop. For some levels, dd is pretty good too. More importantly, it's easy to box. There maybe a time or two the evac will come in handy. I think bards require a lot more attention to get the most out of their abilities. If you multi task well, more power to you, but I'd go with druid.