Here’s an amusing list of 40 things that you’ll see on-screen, but never elsewhere:
- When paying for a taxi, don’t look at your wallet as you take out a note. Just grab one out at random and hand it over. It will always be the exact fare.
- All bombs are fitted with electronic timing devices with large red digital displays so you know exactly when they are going to explode.
- All single women have a cat.
I didn’t read them all, but I didn’t see the one about the hero always finding the perfect parking spot.
DarrenBarefoot.com 
The one about always finding the perfect parking spot is the very first on the list, actually.
D’oh. Ah well, their layout encouraged me to take a more random look through the items.
Here are a couple of my pet peeves:
– when driving to an emergency situation the car is left a distance away because for some reason it’s more efficient to run the last little bit.
– phone conversations never end with a closing comment simply in midstream.
– “I’ll have a beer” never results in any questions from the server.
There is a much more extensive list in Roger Ebert’s “Little Movie Glossary” list.
Something I’ve always wondered: What is the origin of the cliche when a leading character finds out some horrible secret (“I am your father”), and then screams to the sky “Noooooooooo!” (echoing) as the camera zooms upward away from him? I’ve seen it parodied dozens of times, from “The Simpsons” to “Toy Story 2,” but when did it happen the first time?