I use C# 4.0 sometimes at my job and it's actually quite well done. The team was right on the money with their implementation of anonymous functions, functional

I use C# 4.0 sometimes at my job and it's actually quite well done. The team was right on the money with their implementation of anonymous functions, functional programming paradigms (they don't use common naming conventions like map and reduce, though unfortunately), and variable assignment (you basically never need to explicitly state your types in fact, the key word is var, just like in javascript).