Sometimes people ask me for ideas of where to travel internationally, especially for their first time, but I'm not much help because most of the places I've been (and that really isn't very many) aren't really good choices for first-time international travelers, especially with children. Europe is often a first choice for Americans for traveling (as opposed to vacationing), but I've never been there, so I'm not much help.
But now I have the perfect recommendation because I think Mexico City is a great option. It beats Europe easily on practicality since the flight there is much shorter and it's usually cheaper. There is also no jet lag since Mexico DF is on Central Time. Not dealing with jet lag the first time you travel (or any time) is huge, especially with children, especially if you only have time for a relatively short trip, like a week.
Mexico City is also endlessly interesting with so much to do. Museums of all types, history, exploring, Six Flags, pyramids, and so much more that can easily fill a 10-day trip. And I have to say that the food is better than anything I can imagine eating in Europe.
But Mexico also has a bad reputation among Americans because it's supposed to be dirty, crowded, dangerous, and a lot of other nasty adjectives. I was very pleasantly surprised by the city, especially since any city of over 20,000,000 is going to have its issues.
First, I didn't feel like I needed to do anything safety-wise besides my usual big-city precautions. I never felt unsafe walking on my own or with various family members downtown or around Chapultepec. We rode the bus, drove our own car, and took taxis without any safety problems. I was completely comfortable all week.
I was also impressed with DF's efforts to make the city less polluted. This is not the Mexico City of the 90s that was the most polluted city in the world. It felt a loss less gunky than Beijing did when we were there 8 years ago, and Beijing has only gotten worse, much worse, since then. Besides the well-known driving restrictions, the city has also done a lot to encourage bike riding, to replace older buses with cleaner ones, to use cleaner energy whenever possible, and to just make air quality a priority in the city.
We also found the city easy to get around. There are plenty of buses, an extensive metro system which we didn't get a chance to try, and it's very walkable. We also were fine driving outside of downtown. Driving downtown wasn't the best experience, but since we mostly left the car at the hotel, we only drove downtown once or twice.
So yes, I'd recommend DF to just about anyone.