KiCad: Professional PCB Design, Fully Open Source
For a long time, serious PCB design meant paying for an expensive commercial license. That is no longer the case. KiCad has reached the point where professional engineers pick it on merit, not because it is free but because it is good.
The workflow is what you would hope for: a schematic editor, a clean handoff to layout, a capable interactive router, and a 3D viewer that shows you the board before anything gets fabricated. The recent releases smoothed over most of the old rough edges and added the polish that used to set the commercial tools apart.
Because the project files are plain text, your designs work properly with Git. You get real version history and diffs for hardware, instead of a folder full of board_final_v3_REALLY.zip.
Combine that with the fab houses that accept KiCad output directly, and you can get from an idea to a manufactured board for the cost of a few coffees. The gap between having an idea and holding a finished PCB has never been smaller.