LA is slowly improving its transit situation from what it used to be, though unevenly. A light-rail line from downtown to Pasadena was opened in 2003, and the subway system is finally being extended, it seems, through some of the more densely populated area of the westside: http://en.wikipedia.org/wiki/Purple_Line_Extension

The Metrolink commuter-rail system also runs 500 miles of track, and is now a reasonable option if you commute during typical rush-hours. However, it has very little service outside traditional commute hours, and its overall ridership is not very impressive, especially given the size (it gets less daily ridership than the much smaller subway does).