Simple question;
Other than pvp, and in any/every level, which class and stat set up do you think requires the most skill & is most difficult to play, yet effective) and why? Not looking for weird ones like pure strength Mage, they should be fairly normal ones.

Example: pure dex Mage because low health and mana, yet high damage. ( made that up on fly)

Conversely; which may seem easiest? Pve mind you