Avenue C is where the last scene of the movie "Tequila Sunrise" was filmed. One of my friends actually watched the shoot when we were in high school. (One of the characters went to Redondo Union High.) You can see the "Baywatch" beach vehicles driving around during the day. No, "Baywatch" was not shot at Redondo Beach. (It was Seal Beach in Orange County.)
The beach is pretty crowded, especially if it's a really hot day. Try coming at less crowded times. If you come on a weekday at sunset, there are very few here. You and a few other diehards can watch the sun dip down into an orange and pink-tinged horizon. It's something you have to see if you haven't done it yet. At night, it's dark, but you can watch how the sand glows silver under the moonlight. It's a completely different atmosphere at night versus day.
If you want, you can wander over to the pier. There are a couple of late-night bars there. Live bands play at one of the bars on the pier. The beach at night is one of my favorite things to do. It's totally relaxing.