I needed to generate an English wordlist. SCOWL (Spell Checker Oriented Word Lists) comes with a build script that allows customization of what words are included (see the README). Below is a script to generate each supported size. The output from the SCOWL build script (mk-list) seems to be ISO-8859-1 encoded with DOS line endings, so the script converts it to UTF-8 encoding with UNIX line endings.
#!/bin/bash