acid glow's website used to have lots of them! and all great!
but i dont seem to be able to find the site anymore...
the games are also a good place to find sounds
the best really woudl be acidglows website, had soundrips from movies and even old arcade games...
but if u use acidglows sounds, give credit, she (its a she right?) had lots of work ripping them, and i also remember her getting pissed for, i think shadow, using her sounds in deadly species without givin credit.
EDIT:
http://acidglow.planetavp.gamespy.com/here is the acidglows site, you may need winrez to open some files, teh soudns are actually suposed to be used as modpacks for avp2 game...