The thing that almost always came up in interviews that was on my one line of interests was Cyclocross. It is far more specific than "I Like Bikes" and is something different that a lot of people were curious about. Sailing came up as well, but that was more because it was in the body of my resume since I was the captain of the college team. Things like Tennis are just throwaway answers for most resumes since it just equates with "Oh no way man, you own a tennis racket too?".
Basically, if you have something on that line that sounds interesting, it can help give you something to talk about in the interview. Something that helps you pass the test of "do I like interacting with this person".