I have only played Bard and Mage and they both performed decent as solo classes. But from what I have heard Sks are good too. Alch and Wizzies can do it but they need space to work it. And based off of everyting I have heard Necs seem to be the best for solo. But for my final answer I would say Bard. HoTs, PoTs, DoTs, AC buff/debuff, Str/Dex buff, SoW like ability, Armor is best of the non tank types, they have excepitional staying power, this is all my biased opinion.