Sketchup didn't make sense to me. Fusion360 is badass, but way too complicated for the simple stuff I need to do.
My favorite is TinkerCAD. It's very rudimentary, but also very easy to use for relatively simple but functional models.
OpenSCAD is also very awesome, but can take some time to understand. I find it most useful to start with an existing model's code and modify to my needs.