Seattle to Los Angeles

Come mid-October I'll be driving down to LA from Seattle and then flying back to help a friend move. I have a week's worth of time and besides Sacramento and Portland, I was curious where else I should stop for rad railroad museums and really anything at all that'd be interesting to see in person!

Here are several options:

http://www.railmuseums.com/namerica/CALIFORNIA/" onclick="window.open(this.href);return false;

Because I have access to the internet, I also know what the options are. I was looking for recommendations for the best 2-3 that are must sees and shouldn't be missed.

IMHO the Southern California Railway Museum, dba
Orange Empire Railway Museum is a must see, particularly if interested in trolleys/interurbans as well as train/trolley rides.