Another good So Cal hike is San Bernardio Peak. It's over 10k and not nearly as crowded as Baldy, San Jancinto or San Gregornio.
The trailhead parking lot can be a little hard to find, as it's up a dirt road behind the Angels Oaks fire dept. It's a dirt parking lot.
Adventure Parking pass is required and a trail permit can be picked up at the Mill Creek Ranger station.