I came across one of the best flash based games I have seen in a long time. There is a free version and a paid version. I am still working on the free version myself, but i feel that i will soon finish. Everyone I know that has played has become instantly hooked. 

This is a physics based game in which your goal is to move an object from one place to another. The best part is that there is no absolute right way to accomplish your mission. The entire process is up to you. 

You can check out one of my designs here (GTS Link).  In this level, the goal is to move the smaller pink square from the blue shaded area to the pink shaded area. I found 1 way to accomplish this, although I am sure there are far better ways out there.

Play Fantastic Contraption