The monk is probably the easier class. depending on how you set it up, you can just run into a group of mobs and just destroy everything, while being healed just for using your moves that cost spirit. The Demon Hunter is really fun so far as well, but I haven't fully levelled it. Seems a little bit more difficult, but I could just be playing it wrong lol. Rapid fire and tumble and are awesome moves though. (Once you upgrade tumble to hit people while you dodge anyways)