If you are wanting to play with C# in a REPL (although C# has a REPL these days; it's not great but it works), F# could be worth a try. I know the Scheme/ML fam

If you are wanting to play with C# in a REPL (although C# has a REPL these days; it's not great but it works), F# could be worth a try. I know the Scheme/ML family split means not everyone who likes CL/Scheme likes the ML family (and vice versa), but F# is a "good one" for what that is worth.