Well the answer to that question could be broken down to;

  1. If you want a software that’s totally in the cloud then OnShape (onshape.com) is your best option, have I said that it’s free!
  2. If you want a cloud solution that can work offline too then hands down Fusion 360 from Autodesk is your best option, it’s free even for commercial use by small startups!

Personally, after using OnShape and Fusion 360 (more Fusion than OnShape) and though I was a long time SolidWorks user, I’ve never turned back.