Java (yeah even I feel slightly dirty for learning this one, I like getting "close to the metal", and I think I've wasted more time trying to optimize the hell out of the garbage collector than it would have taken just to rewrite some components in C++ for performance, but Java is where the $$$ is for me atm).
Visual Basic 6
Visual Basic .NET (I definitely feel unclean for touching this one, heh)
Can get by:
Motorolla 68k ASM
Picking up new languages isn't difficult for the most part (at least once you're good in one), unless the programming model the new language uses is completely foreign to you. IE, going from a procedural language like C to Java takes some getting used to, especially if you're going to be any good at it (I've seen lots of Java code, and a decent amount of C++ code, that tries very very hard to make object code behave procedurally, and it gets messy, fast).
btw, HTML, XML, CSS, etc are NOT programming languages.