The Rose Bowl happens in Pasadena. The Flea Market is only once a month, its usually the second Sunday of the month. Its a great place to find vintage clothes, antiques and rare treasures. I once found an amazing David Hamilton book that I bought for $15 when it was worth $500.
The Day of Death is one of the most amazing experience you can get from a city like LA. Every year, during the week-end of Halloween, the Hollywood Cemetery becames the stage of the most candid and beautiful celebration of life and death I ever seen.
Salton Sea is not technically LA, but is a by-product of its history and my first-choice escape from the city: one of the world's largest inland seas and lowest spots on earth, a man-made lake in the midst of the Colorado desert, a resort area in the twenties turned in one of the worst ecological disaster of the past century.
If you find yourself in Malibu for any reason, stop by the Pepperdine university campus and check out this grass field. If there aren't any lacrosse practices happening, then you can sit and fell like you're on the edge of the world.