Here are the vacations we've done with kids....
North Shore of Lake Superior - a friend has a family house up there, so we go almost every year. Its a great nearly free trip that involves hiking and hanging in the cabin. The North Shore is gorgeous, lots of waterfalls.
Mexico - we've done the all inclusive in Mexico thing a few times. July isn't any hotter than any other time, and rates are great. The kids play in the pool and we drink margaritas and read. We've also stayed in a private home down there - which is very nice, but you have to do your own cooking.
Cruises - We've cruised Disney twice, but I like the all inclusive better. Cruise is too restrictive.
ABD to Germany - this was wonderful, but expensive. However, if you are going to take elementary school age kids overseas and you aren't a veteran international traveler (or don't want to bother researching your own hotels and sightseeing) this is a fantastic way to do it.
San Francisco/Monterey - beautiful and lots to do out there. From whale watching to Alcatraz to museums.
Camping - we aren't great campers, but the kids really wanted to try it. So we booked a family trip with an outdoor group that specializes in "so you don't camp....." The weekend we went was too hot, and there are reasons I'm not a camper, but the kids got their chance.
Still on the list - Washington DC/Boston/NYC - either in one long trip or broken up into several longish weekends. Also England and France. And we'd like to get to Asia.