The three main options now are Blu-ray, Digital, and 4k Blu-ray. Every movie released in theaters just about gets a Blu-ray and Digital release, and a smaller percentage are released on 4k as well. A lot of new physical releases come with the film in multiple formats.

For example, If I wanted to buy Parasite I'd make a choice between the following options:

• Blu-ray release ($8 on Amazon): comes with a Blu-ray disc and a code for digital streaming.

• UHD Blu-ray release ($10 on Amazon): comes with a 4k Blu-ray disc, a standard Blu-ray disc, and a code for digital streaming.

• Digital ($15 on iTunes/Google Play): 4k digital streaming.

• Criterion Blu-ray release ($20 on Amazon): comes with a standard Blu-ray disc, fancy packaging, additional features and a commentary track, and a black & white version of the film on a separate Blu-ray disc

However there aren't usually a lot of options with older films. Out of curiosity, what are some of the films you haven't been able to find?