One of the greatest jobs (slightly under writing for Major Spoilers though) would have to be working at a Lego store. All day you would be surrounded by an infinite amount of possibilities with access to either discounted or free Legos. One employee apparently thinks like I do and built a Portal gun.
This productive employee took a year to design the gun and then spent three weeks assembling the almost 2,000 pieces, a Mindstorm controller, and blue and orange glowing electronics. I can only assume that he received a promotion after completing his build for all the money he has saved the company on shipping costs. I will again say that Legos are the best toys, hands down.