555 in North American films and television shows

[Caballero]

Very few belong to anyone. Although I heard that some are nationwide (e.g. they will call the same number from any area code.)

If you need a fictitious phone number, you can use

555-01xx where xx is from 00 to 99
they are reserved, according to Wikipedia.

But what is even better is to use the area codes 958 or 959, because Wikipedia says they are reserved area codes. And they look like real cities, but they're really not.