A nice list - nice to see Plankalkül, for some reason.
This popped up recently, and seems in some way related:
[madhadron - The seven programming ur-languages]
(Of course any definitive claim like this is open to their being other opinions, but it’s an interesting breakdown and list.)
Other topics we’ve had in the same vein:
A retrospective on influential programming languages
Programming languages: history and fundamentals (1969 book)