I play Bloons TD6 but I only play it when I need to pass some time especially when it's not enough time for me to draw since I like drawing when I feel like I have at least 4 hours to work on something. Anything less than that my brain can't let me relax cause then it'll feel like I'm on a time crunch.
But if I were to give a more "I will play this for 8 hours straight", probably none at the moment. I promised my partner I'd play the next Oblivion when it comes out, so we'll see. And we don't have much in common when it comes to video games, the only thing we both like is simulator and open world games. Haha.