While doing research into the phrase Deux Ex Machina, I stumbled across this website this morning.

LOVE IT, and highly recommend it to all writers (screenplay and otherwise.)  A few sections had me giggling for several minutes straight. All the best plot device cliches are here: Forgotten Superweapons, Babel Fish, Plot Coupons, etc...  

TV Tropes

Along with The Well Tempered Plot Device

My favorite (from the latter): For instance, Lionel Fanthorpe could never have existed in any genre but SF. Everyone knows, I imagine, the story of the Flaz Gaz Heat Ray, perhaps the most outrageous deus ex machina ending in all literature. There the heroes were, stranded deep in an enemy sector of space, surrounded by an entire enemy fleet with the guns trained on them, when the maestro realized all of a sudden he had only one page left to finish the book. Quick as a flash, the captain barks out: "It's no use, men. We'll have to use the Flaz Gaz Heat Ray." "Not – not the Flaz Gaz Heat Ray!" So they open up this cupboard, and there's this weapon that just blasts the entire fleet into interstellar dust. One almighty zap and the thousand remaining loose ends are quietly incinerated. Where, but in SF, could you do that?