I've played a number of games that make one-off series. Some have been very successful (like FiveM) and some haven't (like Rocket League). However being able to make these series is great as it gives me the freedom to be creative with what I play from time to time.
GTA FiveM Racing Live
GTA FiveM is a phenomenon and the Project Homecoming server is home to some incredible cars & racing modes. I have two series based on my experiences with this.
GTA 4 Racing Live
I played a lot of GTA 4 back in the day and enjoyed racing there too, so it's really nice to go back sometimes.
Rocket League Live
I gave the game a bit of a go when it came out but it just wasn't my thing. These videos show how bad I was!