If you have an interesting story to share, please post an answer, but do not abuse this question for bashing a language.
We are programmers, and our primary tool is the programming language we use.
While there is a lot of discussion about the best one, I'd like to hear your stories about the worst programming languages you ever worked with and I'd like to know exactly what annoyed you.
I'd like to collect this stories partly to avoid common pitfalls while designing a language (especially a DSL) and partly to avoid quirky languages in the future in general.
This question is not subjective. If a language supports only single character identifiers (see my own answer) this is bad in a non-debatable way.
EDIT
Some people have raised concerns that this question attracts trolls. Wading through all your answers made one thing clear. The large majority of answers is appropriate, useful and well written.
UPDATE 2009-07-01 19:15 GMT
The language overview is now complete, covering 103 different languages from 102 answers. I decided to be lax about what counts as a programming language and included anything reasonable. Thank you David for your comments on this.
Here are all programming languages covered so far (alphabetical order, linked with answer, new entries in bold):
ABAP, all 20th century languages, all drag and drop languages, all proprietary languages, APF, APL (1), AS400, Authorware, Autohotkey, BancaStar, BASIC, Bourne Shell, Brainfuck, C++, Centura Team Developer, Cobol (1), Cold Fusion, Coldfusion, CRM114, Crystal Syntax, CSS, Dataflex 2.3, DB/c DX, dbase II, DCL, Delphi IDE, Doors DXL, DOS batch (1), Excel Macro language, FileMaker, FOCUS, Forth, FORTRAN, FORTRAN 77, HTML, Illustra web blade, Informix 4th Generation Language, Informix Universal Server web blade, INTERCAL, Java, JavaScript (1), JCL (1), karol, LabTalk, Labview, Lingo, LISP, Logo, LOLCODE, LotusScript, m4, Magic II, Makefiles, MapBasic, MaxScript, Meditech Magic, MEL, mIRC Script, MS Access, MUMPS, Oberon, object extensions to C, Objective-C, OPS5, Oz, Perl (1), PHP, PL/SQL, PowerDynamo, PROGRESS 4GL, prova, PS-FOCUS, Python, Regular Expressions, RPG, RPG II, Scheme, ScriptMaker, sendmail.conf, Smalltalk, Smalltalk , SNOBOL, SpeedScript, Sybase PowerBuilder, Symbian C++, System RPL, TCL, TECO, The Visual Software Environment, Tiny praat, TransCAD, troff, uBasic, VB6 (1), VBScript (1), VDF4, Vimscript, Visual Basic (1), Visual C++, Visual Foxpro, VSE, Webspeed, XSLT
The answers covering 80386 assembler, VB6 and VBScript have been removed.