Santa Monica Pier.Its not close.The problem here is that realistically the water is like ice.The pier here has Bubba Gumps, rides, shell shops, beach, touch toes in water, amazing scenery.We always see something memorable here.Last time they were filming Sharkanado there that was way cool.Anyway we spent part of the day at Warner Bros, Hollywood sign, Manns and then the pier.
My son is a CM and we have pretty much seen it all this year, I have been here three times and enjoyed it every time.I know there are other beaches but this has a lot more distractions besides the sand and cold water although they have that too.
A Hollywood /beach day can be a real great day away from the disney scene.