Most of all, I like hiking. It's fun, slow enough to let me see things I don't otherwise see, and it's still excellent exercise. Next comes Mt. Biking and then running.
I'm learning to like running, although liking running is going to take practice. I don't think I'll ever get a runner's high, but I can say that I'm enjoying running more now than when I had to run in High School or later on in my 20s and 30s when I ran to try and stay in shape.