1. Manhattan Beach is the most expensive in the area http://www.ci.manhattan-beach.ca.us/
2. Hermosa Beach is slightly cheaper and my favorite http://www.hermosabch.org/
3. Redondo is the least expensive of the 3 cities (2 bd apt ~$1200+) http://www.redondo.org/
4. El Segundo does have a quiet area off of main street with an smaill town feel and is probably the cheapest in the 10 mile radius (not counting dangerous cities of course) but it does have a huge electrical plant, chevron plant and sewage treatment plant between the cute city and LAX but the people I have met that live there love it. http://www.elsegundo.org/
4. Westchester is nice and probably moderately priced
5 Playa Del Ray is a cute beach city just North of the airport and slightly more than Westchester. http://www.playadelrey.com/
6. Marina Del Rey is very nice and pricey too http://www.visitthemarina.com/

Long Beach is great BUT...the area you would want to live in will take you 15 minutes to 45 minutes to get there. They have really done a nice job in Long Beach so prices can be moderate to expensive. Beware parts of Northern Long Beach have bad neighborhoods with gang problems so you want to be closer to the coast. http://www.ci.long-beach.ca.us/

Also if you have kids you do not want them in LA County schools so some areas have there own districts and the ones that do not you might need to send them to private schools.