The third one is definitely rooted in coastal Southern California, but has tinges of other accents. As you pointed out, this accent could be from anywhere in the US as the sound has propogated via popular media.

As a native Los Angelino it sounds to me like a guy in Northern California or maybe PNW who spent a lot of time on the east coast.

It’s different enough from the beachy LA or Orange County sound for me to pick out that there’s some other influence there.