3D Software Recommendations

I'm curious what software are you using to create, edit, mash-up your models?
Must import/export .stl files or share how you're handling that please.

Bonus point is you're on a Mac. :D

I like the ease of use vs. feature capability of Inventor Fusion but it doesn't support importing .stl files, which makes it useless for me 90% of the time.

I am an industrial and product designer at startups, I use the full fledged Inventor Professional on Windows.

Importing STL files is a difficult thing to do overall. Mesh Enabler for Inventor "graduated' from Beta, thus I can no longer use it, so I have the same problem as you. Best bet I have for you is to contact the creators of things you need on Thingiverse, ask them to send you the models in a different format. STEP works quite well, IGES is said to be universal but I haven't had to deal with it myself, etc...

Even though its not designed for it, I actually use Blender. It can import/export stl's and has a huge amount of tools for making models. Its also free.

Took a bit to get used to though. Also, it has no real way of measuring. There is a "scale" section where you can change between imperial and metric and such, but I've found that it doesnt actually change the way the software "measures". It seems to just be for convenience of getting things proportionally correct. However, after doing some digging around on the 'net and observing how big the objects are when I import an stl from thingiverse, it turns out that one blender unit is equivalent to 1mm in the real world.

I know its not the super high end professional stuff, but for the people that dont have easy access to the big league software I say its a viable option.