It is Disneyland and then the rest.
Disneyland captures your childhood, your imagination, if you're with a date - your romanticism. It has rides with thrill, rides with memories of childhood. Battered corndogs as large as your county fair, Star Wars, families, happiness.
Magic Mountain is a bunch of teenagers with raging hormones trying to get at their date. Fun rides, but forgettable. I guess it would be different for folks that didn't live 20 mins away from it.
Knotts is amazing, but at a fraction of which that is Disneyland. Still, Knotts is quaint, has its western charm, and is vastly more fun and rewarding than Six Flags.
Disneyland is the standard. It is nostalgia. It's our childhood put into life. I can never get enough. Haven't had season passes since 2009, but I chaperoned a trip with my son and some of his friends in 2015. I've been around 30-40 times, easily. It never, ever gets old. If you have a woman you are smitten over, it is the peak of happiness. If you are with your wife and children, it is heavenly. Even alone (I've never done this but I would), it would be pure magic, man.