From the Griffith Observatory, use the trail that goes to Mt Hollywood. The hike is gradual with a total elevation change of about 500 feet. Dantes view offers benches in a relaxing spot, although the May, 2007 fire did destroy many older trees which offered shade. A short hike along the ridge east of dantes view offers truly spectacular city views.
Pros: great city and valley views at the top, good workout, dog friendly
Cons: hike is exposed and offers little shade, dogs must be leashed