Anonymous classes are the big thing I miss. (Yes C# has a feature called "anonymous classes" as well, but it's completely different).

What do you still use those for? I can't remember the last time I saw an anonymous class used in a way that isn't superseded by lambdas.

Yeah, I was thinking about that when I wrote the comment. They were most useful for `Observable` objects for event handling in swing; you don't really need that with C# events.

There are still uses though. Lambdas are the future, but there are lots of OO-first libraries that are still quite popular. It'd be nice to create e.g. `new Newtonsoft.JsonConverter() { ReadJson() {...} WriteJson() {...}}` etc on the fly sometimes without needing separate classes.

It's possible in F# though, so nothing dotnet specific is preventing it.

I use them all the time for defining singleton implementations.

    public static final MyInterface SINGLETON = new MyInterface() {
        ...
    }

Java enums are the one thing that I miss in other languages.

If only we could run IL on the JVM

You are painfully correct...

Value types. Reified generics.