I highly highly recommend OnShape.com. It's free, made by the guys who made SolidWorks (nearly identical), doesn't crash, can export STL's or many other formats, and follows a fairly logical build strategy.

I use SolidWorks for my CAD at work and it is extremely powerful, but it's prohibitively expensive for hobby use. Sketchup was what I was using at home until I found OnShape.com. It also works well, but the resolution it offers for smaller parts is pretty poor. However, Sketchup is about as easy as it gets in terms of learning curve.

https://www.onshape.com/