What is the avgn episode where he plays little arcade machines?

The episode you're looking for is called "The Angry Video Game Nerd: Mini Arcade Machines". It was released in November 2014 and features the Nerd reviewing a collection of "mini-arcade" cabinets, such as the "Tiny Arcade" line.

In this episode, the Nerd goes on a rant about how these mini-machines are nothing like the real arcade experience, and how they are just a cheap cash grab. He also plays a few of the games on these machines, including Pac-Man and Donkey Kong, and expresses his disappointment with the quality.

You can find this episode on the Screenwave Media YouTube Channel or on their website.