The easiest and simplest class to play?

[Delekhan]

All EQ classes are easy to play, really. EQ is about mastering the mechanics, so it's knowledge based. Pick a class that suits your playstyle. Sounds like from the OP's preference to solo, stick with Mage, Necro, Enchanter, Monk, Druid, Shaman or Bard I would say. Avoid tanks, cleric, rogue, those kinds of classes require grouping, have severe limitations, and are better for more experienced players focused on the more challenging content.