I live about 15 minutes from Redondo Beach, & work in El Segundo.
Redondo Beach/Hermosa Beach/Manhattan Beach are all nice. They run into each other. The Redondo Beach Pier has restaurants, and a few shops. I like Tony's Fishmarket. It looks out towards Palos Verdes Peninsula, and dinner at sunset is really nice. They have good clam chowder there & their meals are also good. In Hermosa Beach there is a place called the Comedy & Magic Club (18+) which is nice, though I haven't been in a few years.
As Grumpyvet said, the Courtyard by Marriott is a nice hotel in El Segundo, as is the Doubletree, which is nearby. There are a lot of nice restaurants and shopping in this area.
El Segundo Beach is where the Beach Boys used to hang out (that whole area, since they lived in Hawthorne, nearby), and there is a plaque there that says that handgliding started there. The beach is okay in El Segundo, and a little north of there is Dockweiler with fire pits (airplanes from LAX fly over Dockweiler.
You'll see volleyball courts along these beaches.
The beaches go all the way to the Palos Verdes Peninsula, and if you're lucky, you'll see dolphins swim by.
