If you are in Southern Californa and have children, make sure you visit Sea World in San Diego. I have been to Sea World in Florida and Ohio, and this is by far the best one. It has lots of interactive activities and pools where kids can actually touch stingrays and starfish. Kids can also feed dolphins and seals fish (but look out for the seagulls - they try to steal the fish right from your hand). And don't miss the Shamu night show, House of Douse but be prepared to get wet if you sit in the first 20 rows or so. The park sells ponchos for those who want the thrill of sitting close but not the soggy clothes. And before the show is a wonderful tribute to our armed forces.
For adults who love wine, the wineries in Temecula are wonderful and a great way to spend a day. They are conveniently located all in one general area down a main road. You can sample several different types of wines at a very reasonable price.
For kids of all ages, we loved both Universal Studios and the Starline LA Grand Tour with Movie Stars' homes. My daughter enjoyed the thrill rides at Universal and my mother and I enjoyed seeing the movies sets and the special effects. The Starline tour was a great way to cram a lot of Tinseltown into a short time, which is all we had.
Quick Tips:
If you have family/friends in the military, they get great discounts to attractions like Sea World, Universal Studios, Disneyland and the like. Southern California has a lot of military personnel in the area and theme parks are more than happy to show their appreciation.
If you're not so lucky, look for combination tickets. They have a Southern California Value Pass that is sold online at both Sea World and Universal Studios' websites. The pass gets you into both parks as often as you wish for 7 days from the first day of use.
Best Way To Get Around:
We rented a car and it was nice to have while we were in San Diego, as it gave us lots of flexibility. However, we returned it a day early when we went to Los Angeles because the traffic there is very overwhelming if you aren't used to it. Also, our hotel was on the Beach Express trolley line so we could go for FREE down to Manhattan Beach pier, Manhattan shopping plaza, or several stops in between.