I agree with most of the previous posters, with just a few things to add. I have twin 5-year-old girls (just turned 5 a few days ago) and we just got back from a week-long trip.
Epcot OR Animal Kingdom are both excellent choices that will occupy them for a full day. Just check on the park hours, as some days Animal Kingdom closes early. Not sure if that will be the case in the summer. Both parks are fun for adults if you're just exploring them for the first time. In your position I honestly would choose AK over Epcot for kids of that age. And Epcot is my favorite park - but even with all that other posters mentioned (rides and characters) my kids were clearly bored by the end of the day.
There are MANY rides and experiences that kids of that age simply can't do or may find scary at EPCOT. You can certainly fill a day; however my girls are big weenies and really don't like any of the fast, boring or slightly scary rides - this made doing Test Track, Maelstrom, and any of the movies in the world showcase nearly impossible.
I have to disagree with some of the previous posters regarding lines for the characters at Epcot. There are indeed many character experiences. But if you're going to do them, you need to plan ahead. Most are little lines outside of the different country pavilions. They show up once per hour, keep the line open for about 15 minutes, and then shut down the line. Anyone in line gets to see the character, but if you're too late you have to wait for the next time.
And, hold onto your boots - the line for Anna/Elsa was 4 HOURS LONG, on a Wednesday in January. I'm going to be judgmental here, but what ridiculous person would stand in line for 4 hours for a character meet-and-greet? We certainly declined to do so. My kids were disappointed, but they got over it. Though the sad look on their face when we first discussed it is something I wish I didn't have to experience. My point here is only that you shouldn't get them psyched up for a particular character, the way I did, because it just might not work out.
With all that said, you can't go wrong with any park. I just don't think DHS is a good all-day choice for young kids.
Epcot OR Animal Kingdom are both excellent choices that will occupy them for a full day. Just check on the park hours, as some days Animal Kingdom closes early. Not sure if that will be the case in the summer. Both parks are fun for adults if you're just exploring them for the first time. In your position I honestly would choose AK over Epcot for kids of that age. And Epcot is my favorite park - but even with all that other posters mentioned (rides and characters) my kids were clearly bored by the end of the day.
There are MANY rides and experiences that kids of that age simply can't do or may find scary at EPCOT. You can certainly fill a day; however my girls are big weenies and really don't like any of the fast, boring or slightly scary rides - this made doing Test Track, Maelstrom, and any of the movies in the world showcase nearly impossible.
I have to disagree with some of the previous posters regarding lines for the characters at Epcot. There are indeed many character experiences. But if you're going to do them, you need to plan ahead. Most are little lines outside of the different country pavilions. They show up once per hour, keep the line open for about 15 minutes, and then shut down the line. Anyone in line gets to see the character, but if you're too late you have to wait for the next time.
And, hold onto your boots - the line for Anna/Elsa was 4 HOURS LONG, on a Wednesday in January. I'm going to be judgmental here, but what ridiculous person would stand in line for 4 hours for a character meet-and-greet? We certainly declined to do so. My kids were disappointed, but they got over it. Though the sad look on their face when we first discussed it is something I wish I didn't have to experience. My point here is only that you shouldn't get them psyched up for a particular character, the way I did, because it just might not work out.
With all that said, you can't go wrong with any park. I just don't think DHS is a good all-day choice for young kids.