I don't know of the good apps for kids seeing as I don't have any, but what apps are you looking for for yourself? I have apps of all kinds so I can probably help you there.
I use my iPad a lot for reading the news, and I really like the Politico, AP, and USA Today apps. I like Fox News for streaming news from 9a-5p as well as see videos from their primetime shows.
For humor, I really like The Onion's app.
If you're a Twitter user, I personally like Echofon.
If you're a Netflix member and have streaming in your plan, Netflix is a must.
I'm not a huge gamer but I like Words with Friends and Sudoku a lot. Dice with Friends, which is Yahtzee, is fun too.
My suggestions are kind of dull, I apologize! Browse the forums for other app ideas. What I did too was just look through iTunes’ most popular apps in each category and found great ones that way.