This is a great website that you can filter no equipment, how many students, what kind of games, and age. There are thousands of fun options. One game that I like to use in PE is "10 second tag". It requires no equipment and only needs a few students to play.
Here is a link to tons of differnt activities. At the top of the webpage, you can narrow down what grade level and activity time. Some games require equipment, but a lot will not.