By that I mean languages where they are stable and the standard has stopped being actively worked on, and they offer something interesting by studying them.
I am not looking for normal imperative /procedural languages that have stopped being worked on (i.e. C-like) unless of course it was something that c is based off like ALGOL.
They can be languages that run on any platform (not just unix/osx/win), it can run on a toaster for all I care, I just want it to be something interesting.
I am looking to be amazed :)
You should check an esoteric languages.
There is a site, esolangs.org that has a huge list of the esoteric languages, an informations about paradigms/concepts, a list of ideas and many more.
From the esolangs.org, the esoteric language is:
An esoteric programming language is a computer programming language designed to experiment with weird ideas, to be hard to program in, or as a joke, rather than for practical use.
Here are some examples from that site: