My family has been to Disneyworld a few times, and we also like to explore real places as well--went to Venice last summer. I can see the appeal of both. Disney parks aren't going to get you out of your comfort zone, but they do have a distinct charm, however artificial, and a guaranteed consistency and welcome that other touristy experiences--and don't kid yourself that Venice and Machu Picchu are not tourist traps--often lack.

Venice in particular is a great example of a place that has basically become a Disney-lite type of experience. Sure the city buildings are ancient and the canals and alleyways make for a truly unique location that's fascinating from a historical point of view. But it's smelly, hot, hard to get to, utterly packed with visitors; the lines are long, the attractions aren't always what they are cracked up to be, they nickel and dime you for better access and shorter lines, you have to carefully choose restaurants and food vendors, the "shopping" is barely different than what you find at an upscale mall in any large city in the world, there are pickpockets and scammers, the rides cost extra and aren't always working, the gift shops are overpriced and often terrible quality. All in all, Venice may be more real, and if you're a history nut you can probably see some interesting settings from old stories, but if you are wanting to have fun on your vacation and experience something pleasant that you can't normally do, Disneyworld is cheaper, easier to get to, less crowded, and a lot more fun.