Honestly, Minecraft. I used to tease my kids about it, because the graphics are "backwards" from modern games. Finally, after much prodding over the years, my son made me sit down and play with him. I loved it. I enjoy building things. I enjoy exploring. After I learned the game, I play on hard survival mode. Even doing tedious tasks such as removing a mountain because it is in the way is almost theraputic. There are so many things you can do with the game and by keeping it in "hard" mode, it keeps me on my toes. Sometimes I die (and if I am the only one playing, I will usually revert to the last saved. Sometimes that has meant losing nearly an hours worth of work, but my gear would take a lot longer to replace.)
Other things...
Watch a new series on Netflix/Hulu
Watch an old series again (I love House, M.D.)
Youtube (find out about new and interesting topics, things you haven't looked into before...I once thought about starting my own channel and did a lot of research into that.)
Read
Walk, nature trails (we don't have a good nature trail near where I live right now.)
Ride my motorcycle (listening to music while I ride)
Other hobbies...