Waterfox is the most conventional alternative. If you want to be up and running in as few steps as possible, this is the best choice.
Zen is the most unique. If you're looking for a cutting edge and somewhat experimental browser, this one's pretty great too.
LibreWolf is the most private. It's a halfway point between Firefox and Tor, but if you think it's settings are too extreme, you can dial them down on your own pretty easily (it's much easier than disenshittifying Firefox).


