http://sfy.ru/
http://www.script-o-rama.com/snazzy/dircut.html
http://www.imsdb.com/
be sure to not use any that say 'transcript' or 'transcription'... those are not actual scripts, but only what some fan has written down while watching the film/show...
and keep in mind that none of those will be spec scripts by unknown newbies, so keep your specs lean and clean, save the fancy personal style touches till you've made a name for yourself..