I love hiking at Torrey Pines, there are plenty of challenging and not-so-challenging hikes that all have gorgeous ocean views, a welcome breeze, and interesting terrain.
You can park for free along coast highway and hike up the park road or along the beach to access the trail heading up into the park, if you don't mind adding the additional distance to your hike.
My favorite view is coming down the South Fork Trail to the Broken Hill Trail - the broken hills are amazing and you come upon them from such a great viewpoint. This trail also takes you all the way down to the beach and you can head back up along the Beach Trail or Yucca Point trail. Starting at the far end of the park avoids much of the crowds, too!
For less elevation gain, the Guy Fleming trail is gorgeous (I love this part of the park - amazing terrain and great views and it's pretty short!). The Razor Point trail and Parry Grove trails are worth it, too.
You can't go wrong at Torrey Pines if your looking for some amazing hikes along the coast.