Examples of actual play
Critical Role
Probably the most well known example of an actual play show is Critical Role. With more than 2 million YouTube subsribers on their channel, an Amazon show based off their game, and their own streaming service, these nerdy voice actors have shared their love of Dungeons and Dragons for almost a decade. The game style is long form campaigns, usually lasting several years. Occasionally there’s a one shot, or a shorter campaign.

Dimension 20
Dimension 20 is part of Dropout Tv, with only select episodes available on Youtube. The campaigns tend to be short, with several coming out a year. The game is primarily Dungeons and Dragons. Usually headed by Brennan Lee Mulligan, they occasioanlly invite a guest GM.
LA By Night
This game is part of the World of Darkness Vampire the Masquerade. It ran for 5 seasons of about 10 episodes each. It follows the ambition and heartache of an LA based Coterie as they face the dangers of the night.
All the others
There are numerous other fantastic actual plays.
Bookshops of Arkham by Chaosium, and the Calyx by Becca Scott are both fantastic short form campaigns in Call of Cthulhu.
A long running Comic Con favourite in the realm of DND is Acquisitions Incorporated. Another popular DND show in podcast form is Dungeons and Daddies.
If there’s a system you’re curious about, someone out there is sure to be playing it.