2D and 3D modeling and animation. However, an artist's job is not an easy one. Experience and knowledge of these packages or others can put you skills in high demand. 3D Artists are in very high demand these days. This demand is not just limited to the Interactive Entertainment Industry, but the Television and Film Industry as well.
Demand is very high making it somewhat easy for beginners to get their foot in the door.
May use any media for portfolio. However sample videos of animations on tapes is strongly recommended. A familiarity with more than one graphics package is helpful.