I'll watch anything......
Other than cycling, my favourite has to be baseball. I used to play before I 'retired' and I still do an annual US trip to watch the Major League teams. Last year it was San Francisco where I saw the Giants and took in a couple of Athletics games at the Oakland Coliseum. The Giants went on the win the World Series, so fantastic atmosphere at the ball park on the Bay. Not sure where yet this year. I quite fancy Washington to see the Nationals, perhaps travelling up to Baltimore to take in a couple of Orioles games as well if I can figure out a way of getting in and out of Baltimore safely!
Also, motor sports, not surprising as I'm not far from Brands Hatch and have enjoyed many hours bother watching and driving there. I have to say though that I haven't been much over the past couple of years since cycling has become the number one interest, so I might sell the car and get (yet) another bike :-)