You can do healthy alternatives of stuff they like - for example, I make 'chicken nuggets' with cut up tenderloins, a combination of wheat germ and whole wheat bread crumbs, and a quick-fry in olive oil, and then finish the cooking in the oven. You can sneak a lot of veggies in spaghetti sauce (for pizza or pasta) and put butternut squash in mac & cheese. I put EVERYTHING into pancakes - you'd be shocked!
There are some good cookbooks in bookstores/libraries. Sneaky Chef and Deceptively Delicious are 2 best sellers. Rachael Ray has some stuff in her cookbooks and magazines too.
Getting kids involved in the cooking and the shopping can be helpful too. Also, if you can grow some of your own vegetables this summer, that's a great incentive. Stuff that comes out of the ground fresh is better than what's in the stores anyway.
I agree about not making separate meals for everyone. And your husband has to get on board here!
There's some statistic about how kids have to try things about 8 or 10 times before they know for sure whether they like it or not. It has to do with hyper-sensitive taste buds. Don't give up.
You can also use a comprehensive dietary supplement like Reliv's Now for Kids to give them the DHA the need for brain development, and all the essential nutrition in one blended drink. Much better than instant breakfast shakes, and certainly better than those kiddie vitamins that carry warning labels and aren't absorbed - waste of money, say most doctors. Happy to give you more info on this - it's been used world-wide for many years and is improving children's health exponentially. We have a nutrition crisis in this country, with more and more kids getting "adult" diseases - and this is the first generation that will not live longer than their parents because of it. So it's a good time to take action.