A couple of years ago I found out about really neat game engine that is flexible enough for all beginners to understand how it works. It was fun testing it back then and I used it to create a small presentation. Now days Unity becomes a real professional tool with big forum community and huge asset store. You need to install Unity Web Player to preview this engine project in your browser. Take a look at this quick presentation I have created back then (it took me just a couple of hours to make this presentation including getting familiar with program environment for the first time) :
Unity is a game development ecosystem: a powerful rendering engine fully integrated with a complete set of intuitive tools and rapid workflows to create interactive 3D content; easy multiplatform publishing; thousands of quality, ready-made assets in the Asset Store and a knowledge-sharing Community.
Take a look at Made With Unity Gallery at official website:
My recommendation is to arm yourself with some spare time and creativity and I promise you will have good time playing with Unity 3D.