Go&learn C++. It blows my mind how often people confuse C++ with "C with classes" in 2008. Granted, C++ isn't as sexy as OCaml, but it's still C plus some rather nice extentions that (finally) got trully portable and work as advertised.

Powerful templates plus multiple inheritance give you a very impressive weapon to play with. C# and Java don't even come close.

And please... 99% of software on Windows, Mac OS X and Linux are built using the same stuff: C/C++/ObjectiveC.