I'm not a sports fan at all, but I had a great time earlier this year when I checked out a baseball game at Knights Stadium. It's a little ways out of town, but it was worth the trip. I went with a large group of work associates, and we had fun even though I didn't watch the game at all.
It's a great night out for children and families or large groups, and if you pay attention, there are usually good deals where you can get cheap or free tickets. Even if you're not into sports, it's a great alternative to another (freakin') night in a bar.