I know this is meaningless drivel. But i think this is the appropriate forum . Suppose you are starting a project from blank slate[I mean like not maintaining or upgrading any existing S/W]. And you are proficient in both Java and C#. Which one would you prefer to do write an front end enterprise software?
@bear is correct, if you pick C#, you are forcing your self into a Windows world. Given how badly Windows 8, the Surface, and Surface Pro, are being accepted in the market, that seems to be a dangerous decision.