Interstate 5, is the quikest way. If you are leaving Friday afternoon to early eveing I would actually drive to Oakland and grab the 5 via the 580 because The 156/152 bottlenecks during rush hour towards Interstate 5. You can be stuck for a an hour or two, but if you are leaving during non peak hours(late night or early am) you should be ok.
101, driving down the coast is really nice. For the FIRST 45 mins, then it all looks the same after that. And if all the hills and curves are not exciting enough for you to drive, you may be able to drive a few hundred miles of hills and curves IN THE FOG. ONCE I drove to Monterey to watch the sunset over the water and then drive down the coast, ONCE. Well after we watched the sunset and started driving, the Fog rolled in and it was not fun. Again depending on time of day it may not be a factor.