Brainfuck
Pros:
- You get to say "fuck" in a vaguely technical context
- Elegantly minimalist syntax
- Truly deranged control flow and memory management makes comprehending code a nightmare (fun)
- a masterclass in doing a lot with very little
Cons:
- Saying Brainfuck is the best esolang is like saying that the beatles are the best rock band of all time: It's a defensible opinion, and it might even be true, but it's also the least interesting thing you could have added to the conversation
Untyped Lambda Calculus
Pros:
- Actually writing anything resembling a real program is probably harder in this than any other programming language
- "Oh? 3? You mean λf. λx. f(f(f(x)))?" statements dreamed up by the utterly deranged
- Not having types when a type system is the lowest hanging fruit imaginable is the kind of thing only a real gamer can pull off
Cons:
- Far too important to the history of logic and computing to be a genuine waste of your time
Befunge
Pros:
- Near-impossible to write a compiler for
- Self-modification and geometry are the kinds of things you only add to a programming language if you are truly deranged
- You will never get the word "fungeoid" out of your head
Cons:
- Lacks the gamercred of later fungeoids
Whitespace
Pros:
Cons:
C
Pros:
- Theoretically powerful but without guardrails for sanity, like god intended
- Near impossible to write secure, performant code in
- Type system/pointer math is the kind of thing only cooked up by deranged mathematicians
- I, the dark wizard malloc, will cast you into the void star
Cons:
- Somehow still industry standard