.... or DisneySea, or Universal Studios in Osaka, for that matter. (But according to reliable sources, DisneySea is better than Disneyland.)
First of all, I, Fat Geisha, and her darling husband, Samurai T, are waAAAy too over-aged (I hesitate to use the word "old") to be interested in kiddy things. Oh all right, we recently went to Universal Studios Singapore and had a whole lot of fun, but that was because there was nothing much to do in Singapore in the first place. I am most certainly NOT going to spend my Time and Money travelling all the way to Japan, and blow an entire day in the company of Mickey Mouse and friends. Yes, only if you have never been to Disneyland (or Universal Studios) before and DESPERATELY want to go; or you have no choice because you are bringing kids along and need to entertain them.
Second, it is pointless to review amusement parks. They are all the same around the world. And once you get in, it would be an utter waste of money if you do not stay the whole day, and half your time will be standing in queues awaiting for rides anyway. :P
Why waste your precious time at these amusement parks? Seriously? Japan offers a whole lot more interesting sites and sounds that is only available in their country. Everytime we are in Japan, we bemoan the lack of time to explore this or that place, and have to make ourselves choose the more important things to see. It is like when some people visit a new country and choose to eat MacDonalds instead of the local food. Like Hallo?? Why bother to leave your country then? Isn't the point of going overseas to broaden one's horizons?
It always gets my goat when I see tourists huddling in their tour bus instead of going down to walk around the site. Mount Fuji too unspectacular for you? Need to walk too much at Meiji Shrine but can walk for miles at Ginza for shopping? Stay home, please.
And that is the main reason why Samurai T and I will never take a tour package to Japan. Almost all packages will include a day at an amusement park, or worse, 2 days at TWO different amusement parks (shudder). If you get really desperate, at least go to a more interesting park, like Hallo Kitty Land. At the very least, you know it is only available in Japan.