It depends. Sometimes I just enjoy chilling with some friends and watching movies, playing games, etc.
Other times I just enjoy being in my room and reading, or listening to music, although I find it's very difficult for me to just lie back and relax, only listening to music.
I also like to lie on my bed and just relax, or think about things. Sleeping, and dreaming can be very soothing if I can do either at my leisure. Having to wake up or worry about doing something tends to ruin this for me.
I also like to tune out the world by playing video games. I think it's one of the easiest ways for me to get recharged because I have the leisure of starting and stopping whenever I like.