As for junglers, there are 2 types. Carry and Support. Carry jungles like Nocturne and Shyvana get gold and farm to be a semi-carry. Support junglers like Maokai and Alistar focus on getting their lanes fed and move into a team oriented support role. Personally I prefer carry junglers, Nocturne is my main pick if I have to jungle. Good clear time, good duelist, great ganks before 6 and fantastic ganks after 6. Due to Duskbringer and Passive you can build him relatively tanky while still outputting respectable damage.