We've only been to WDW in Orlando and Disneyland in Paris. I REALLY want to go to Disney Sea, but that may wait a few years. My daughter keeps asking about California, but it looks so hard to navigate!
The Disneyland Resort is EASY to navigate. Only two parks, located across an esplanade, which makes it super easy to parkhop, and doesn't require the level of planning that a WDW trip does. Downtown Disney is also right there at the parks. The hardest decision will be where to stay, as there are only three Disney properties and they're all pretty pricey. They do help keep you in the Disney bubble though, which is the biggest downfall of having to stay in one of the "good neighbor" motels that are all near the park. The Disneyland board has lots of great information.