Several people commented on their programming language knowledge in this thread so it seemed like it would be fun to let us all go.
HTML, CSS, etc. don’t count. And you only need to have at one time been proficient for it to count.
Myself:
x86 assembler
C
C++
D (soon)
Perl
Java
SQL (Postgres, Oracle, MySQL)
VBScript/ASP (but not .NET)
PHP
Javascript/DHTML
Make
QBasic
Lua
Bash shell script
C
Perl
Common Lisp
Scheme
Emacs Lisp (GNU Emacs, dunno about XEmacs)
Objective-C
Pilot (… not that that’s anything to be proud of)
GW-BASIC (hey, it beats Pilot)
QBasic (came with Windows 95)
Python
Ruby
Fortran (various dialects, mostly FORTRAN-77)
Parrot assembly
x86 assembly
PDP-8 assembly (Turing tarpit, where everything is possible but nothing of interest is easy. Weird, weird computer.)
PDP-11 assembly (Simple. Orthogonal. Love it.)
VAX assembly (Polynomial-solving opcodes. Think about it.)
Bourne shell (bash and zsh mostly)
BEZ
Java (not AspectJ or anything else, though)
Javascript (which is not related to Java at all)
Make
CORC and CUPL (two very similar crufty old teaching languages)
Brainfuck
If I were to list languages I can write with a short reference to hand, the list would include Lua and System/360 assembly and some others. I can read COBOL but my hands would attempt to strangle me if I tried to write anything substantial in it.
I would feel comfortable writing applications in:
C
C++
Java
Motorola 68000 assembly
DXL
[edit] Holy crap I feel inadequate now. 
dgrdfd: Learning programming languages is easy. C, C++, and Java, for example, will take you a good deal of the way to learning Perl, Python, Ruby, and Lua. Motorola 68000 assembly was explicitly based on PDP-11 and VAX assembly, so you have a foothold there as well. Offhand I’ve never heard of DXL.
Learning new paradigms is difficult. People who use Common Lisp approach problems much differently compared to people who use Java, for example. Switching gears from one paradigm to another can cause much thrashing about.
None. I bailed out of engineering after I got the degree and I’m a sale and marketing manager now.
Yeah, I guess I am still pretty new and haven’t really had the need for a lot of different programming languages yet.
The DXL stands for DOORS Extension Language. DOORS is a requirements management tool we use at work and DXL can greatly simplify your life if you use DOORS.
Pointy-hair. 
Perl, FORTRAN, IDL, bash and csh.
I’m probably showing my age here, but I cut my teeth on Fortran (on punch cards!) and grudgingly learned Basic a few years later, back when them new-fangled Personal Computers arrived. That’s about it.
At some time I have used all of the following – professionally unless otherwise noted:
IBM Macro-assembler, PDP-11 Assembler (college only)
APL (college only)
(ba)sh, (t)csh, DOS “shell” langauge
yacc, “more”
PHP, Perl, ASP
VisualBasic (blech… :o)
JavaScript
XSL/XSD (xml file parsing/definition)
C, C++, Java
Fortran
BASIC (sigh…)
SQL, PL-SQL, HQL, JDO-QL (the latter two are ORM overlays on top of SQL)
IBM 360 Assembler
Fortran
Pascal
PL/1
COBOL
Basic
clist
ReXX
csh
DL/I
SQL
PL-SQL
The Hell!? 
I meant “Make”. Sorry.
Also, I remembered another one… Pascal.
Cobol
Fortran
Basic
Pascal
Of course in my day there was a 24 hour turnround before you got your job back from the mainframe.
And I used to be pretty good at deciphering hexadecimal dumps (ah, there’s the registers, now what caused the crash?)
I used to enjoy doing that, and a two-foot thick pile of stripy paper covered in hex was always a useful tool to ward off anxious management when something had crashed. Oh happy days…
APL
Assembly
Basic
C
C#
csh
FlexPDE
Forth
Mathematica
PL1
SAS
Scheme
VB
And, yo, Derleth, are you really fluent in brainfuck? Is it possible to be???
GW-Basic (back in the days…)
C
C++
Objective C (working on it…)
Java
Javascript
Max (The multimedia visual programming language)
Puredata
CSound
Supercollider
The last three are specialized with Max and Puredata differing the most from the traditional form of a programming language, but visual languages (like Labeview) should count I think.
ZX-80/81 Basic
Z80 Assembler
Basic
6502 Assembler
6809 Assembler
ICL COBOL
FORTRAN
Pascal
Modula-2
DOS Batch
X86 Assembler
Z8000 Assembler
Prolog
csh
C/C++
Visual Basic/.NET
Perl
awk/sed
Python
bash
php
kix
Rexx
tcl
keykit (midi programming language)
Many of these are scripting tools, but qualify as useful languages as well.
Languages I completely failed to understand include:
LISP
SmallTalk
Si
Basic
FORTRAN
CMS-2M
C
PL/1
Ada
C++
Java
Several diffferent instruction sets (~5)
Of those, I am most comfortable with C/C++
I bet it’s not on his(?) CV (and he missed out Whitespace, surely everyone knows that?)
X86 assembly
C
Bourne shell script, awk, sed (I’ve edited make files I wouldn’t say I fully understood them)
Pro*C
PL/SQL
SQL
Oracle Forms 
and Reports :eek: *****
Have worked in Java and C# but I’m not proficient in them.
***** I suppose they’re tools or IDEs really (I don’t know if they’d qualify as 4GLs) but there’s a lot in them that isn’t just PL/SQL
Basic, Qbasic & VB
Fortran
Cobol
CL
RPG & RPGLE (my strong suit)
PML
My SQL is weak.
That’s it, I am a boring business programmer that supports ERP.