Mt. Lowe - Mt. Wilson area is good. There're some hidden waterfalls to find etc.
Or Griffith Park if ya don't want to drive.
The devils backbone above Malibu is cool too.
Yeah, eaton canyon to mt wilson toll road (through henninger flats) is my personal favorite. Griffith is too crowded although someone told me recently that there are lesser known trails there too. gotta look up devils backbone thanks man!