I'm kind of a "game snob" - generally we get more abstract strategy games to play with the kids - Quoridor, Blokus, Gobblet (off-topic, but if you've never heard of them, they're all great games for adults as well as six-year-olds, by the way - fun, very easy to learn, lots of strategy).
Despite my game snobbery, we got the Magic Kingdom game for the kids for Christmas (since we're going to WDW in March). And I have to say, I've been pleasantly surprised. It's actually pretty fun. There's some strategy, some luck - it keeps an adult occupied, but a six-year-old can still win. And who can argue with the Magic Kingdom theme?
If you don't know the rules, here they are:
1) The map basically looks like the WDW Magic Kingdom.
2) You draw five "attraction" cards - one from each land. These are the attractions you have to visit.
3) You move by rolling a regular die. If you're at a railroad station, you can roll the railroad die instead - if you roll the RR sign (on half the sides), you can instantly move to another railroad station.
4) If you roll a 1 or a 2, you get to draw an "event card." The event card can be anything from "take another turn" to "move 6 extra spaces" to "move another player to another spot on the board", but it's always a good thing for you or a bad thing for another player.
5) If you land on the Mickey or Donald pieces, you get their autograph (and move them to another space on the board). You can use the autograph to "cancel out" another player's event card.
6) First person to visit all their attractions then leave wins.
In my experience, the game is almost always very close at the end, which is fun and exciting. My daughter and I sometimes pick ten (or even fifteen) attraction cards to make the game last longer...
To top it off, kids learn about linear optimization at the same time - the game is basically the classic "traveling salesperson" problem. If only they could add queuing theory, then the game would basically be an excellent introduction to "Line Avoidance at Disney 101"