Disneyland, Disneyland, Disneyland.
DCA has its charms, but they pale when compared to the many delights of the original, DL.
DCA is more of a conventional theme park, with more predictable theme park rides -- a coaster, a raft ride, a carousel, etc. Characters are few and far between, and so is the sense of enchantment that is the hallmark of DL.
DL's attractions try to tell a story and offer a touch of magic. (As wonderful as "Soaring Over California" is, it can't begin to compare with the "Haunted Mansion," "Splash Mountain" or "Indiana Jones" - each of which is a certifiable classic.) The theming, landscaping and even the food in DL is better than DCA, too.
And - need I add? - you get a LOT more bang for your buck in DL, with about three times as many attractions for the same price.
Finally, DL is an American icon -- a vital and significant part of our popular culture. Everyone should see it at least once!!!
