Photoshop CS 6. I still use it to this very day. Doesn't require a subscription. Otherwise I'm at a loss for what could be used.
working on Apple OSX:
I am on Photoshop CC at the moment, but still have CS6
what is better in CC:
Cameraraw support for new camera models
better Raw developing: ( ACR has some new tools- almost on par with LR CC)
CS6 it is 64 bits, and runs on Mojave ( my latest system) but the installer is not, so it has to be installed on an older system and upgraded to that new OS- what i notice is it is not working well with actions; after some time (- on OSX 10.12 and 13 it is 5- 10 minutes) they stop.
Just checked mojave : the action works 5 minutes after that: spinning pizzawheel and a system restart!
It officially lost support after OSX 10.11
Other than that it seems to work and the new improvements over the last years are minor.
I have bought a copy of Affinity photo and it is a very good program with development and new added features.It also makes good use af the processor cores. There are very good learning videos on their website.
I am now on the LR+ photoshop CC wagon but am ready to jump off if it becomes to pricey or otherwise...