Let's include here not only Programming Languages, but also Query Languages and Markup Languages.
C - after English, probably the most basic 'language' anyone working with Computers should be familiar with. Can't say I'm a complete expert, but I've had to work with C for a long time now. Did I mention how much I love pointers?
C++ - I only started working recently with it (if you take into account the object-oriented aspect alone - pushing the structural aspects up to C knowledge).
C#/Java - both fall in about the same category - if you know one of them, switching to the other is not that hard. Technologies (Java vs .NET): now that's a different story. We could include here LINQ, ASP, JSP and other mumbo-jumbo, but again, once you get how to work with a language, adapting to various technologies is rather easy.
80x86 Assembly - you cannot always avoid assembly I guess, but personally I try to stay away from it - had a course on assembly languages and an additional lab for ATMega64 microcontrollers. Can't say I hate anything more than branches (writing loops in assembly? better shoot me in the head instead!). The top of the garbage was the Operating Systems Design course.
HTML, CSS, Javascript Batch - had to deal with them, but I can't say I'm an expert - I run away from HTML as much as I can, mainly because writing hardcore by hand is tedious, boring and heavily frustrating. I find Javascript this messy goo - though it was the very first 'language' I ever started programming in (if you don't count an afternoon of Pascal before that, which was a complete disaster).
PHP - I prefer JSP and ASP as alternatives. Weakly typed languages drive me insane for some very odd reason I totally understand.
VHDL - FPGA Programming made me want to throw my computer down the window two years in a row. Anyone who hasn't bothered with VHDL and complains how long some programs take to compile, get Xilinx, and synthesize some decent project in VHDL. You'll never-ever hate compilers again. Getting an FPGA board to behave at a hardware level any way you want is pretty awesome, though.
MSQL & MySQL - I work with them when I have to. Though I know how to make basic queries, I know next term I'll be going back to hardcore SQL (database courses are always horror stuff). Used to be able to do some pretty nifty queries - since I didn't have to do anything more complex than an INNER JOIN, I kind of lost my touch.
Prolog - I totally lo-lo-loved it. Being able to write a quicksort algorithm in 3 lines (of decent maximum length, say... 60 characters/line?) rocks! Logic programming is a bit weird at first, but it has its uses in Artificial Intelligence and Natural Language Processing. Neat course, neat experience, can't wait to get the chance to experiment with it more.
Haskell - My dear lord, I had a teacher obsessed with Haskell, and prototyping in Haskell. He gave me this horror distributed system to port it on Windows Azure. But again, I guess like any other 'obscure' language, Haskell has its own uses. Learned a few tricks, and though I haven't worked with it in a year, I'm certain I could remember rather easily.
LISP - Half a semester and a project on a different subject in LISP was more than enough for me. Too many brackets, some very obscure concepts... let's just say if I see a LISP program I know what it is, but I'd rather stay completely away from it! Haskell is a much better Functional Programming language.
An enumeration doesn't make anyone an expert in everything. It just means that at the very least, the programmer recognizes the language/understands vaguely what's written there. Since I didn't include Python for example there, it means that if you gave me a piece of code in Python, I would be completely clueless of the language (and probably not even understand what's going on there).