Bicycle Thieves (Vittorio De Sica)

Set in post-WWII Rome, Antonio's ability to support his family is heavily dependent on accessing his sole mode of transportation: his bicycle.

On the first day of his new job, his bicycle is stolen and, along with the help of his son, Antonio is determined to track down the thief and get his back bike.

I am just now realizing how this is a bit similar to the plot of Pee Wee's Big Adventure (the stakes for Pee-Wee considerably lower, of course) but, it's totally different...but you should probably watch both. They're both excellent!