I've noticed a lot of people looking for a way to delete a list (based on search terms used to hit my blog). There's a built in command called "forcedeletelist" which will do the trick. Note that there's a bug with the help message for the command:
C:\>stsadm -help forcedeletelist stsadm.exe -o forcedeleteweb -url <url>
Notice above that it says "forcedeleteweb" - have no fear though - it won't delete your web - it's just a typo in the help text. I'm not sure why they called it forcedeletelist instead of just deletelist - if you disassemble the command though you'll see that it's calling an internal method called ForceDeleteList on the SPWeb object - this in turn calls ForceDeleteList on the unmanaged SPRequestInternalClass object. If you're looking for other list related operations check out these postings: Import, Export, and Copy Lists and Import, Export, Copy, and Delete List Items.