Order off the kids menu - or share a regular entree with two adults. As long as you don't have a huge appetite, I find the kids menu to be adequate for in-park meals, especially when I'm on a budget. Also, any kind of hot dog/corn dog/mac and cheese hot dog/etc is typically the best bang for your buck. Hot dogs run about $6-$7 and include either chips or sliced apples.
When I'm not on a budget, definitely Carthay Circle and Napa Rose. Avoid Blue Bayou, unless you're really into the ambiance. The food is just not worth it for the price.
Definitely bring a reusable water bottle and just fill up around the park during the day. Unless you're a huge soda drinker, you'll save a ton of money this way. You can even fill up at the soda fountain (with water) in self-service places like Plaza Inn and Rancho del Zocalo. The water there is filtered for the sodas and tastes better than the water from the water fountains. (Yes, I'm a water person and think that not all water tastes the same.) You can also ask for a cup of water (no charge) at any place that serves soda from a fountain. I'm actually not a soda drinker and I do this all the time, just to refill my water bottle.
I feel cruel doing this, but there is a Food Photo thread here on MC. Perhaps there you'll find what we've all been talking specifically about here, and make further decisions based on portions, serving sizes, etc.
And then, you can go visit this great site which not only posts current menus for all the eateries throughout the parks, DTD and hotels but pricing as well in case you want to consider some specific budgeting before to arrive.
Like you I have small kids. They have been eating at the parks since they were two years old. In terms of kids meals, the priced aren't much more than a happy meal but are healthier. There are the usual favorites for kids but portions are perfect for little ones and all come with healthier sides.
I have spent the morning looking at breakfast menus in the parks. I found way more options than I thought I would, and the prices are pretty reasonable. I used to be one of those people that had to eat quickly after rising in the morning. Now I have changed to not eating breakfast, until I have been up a while.
The first morning, of my up and coming trip, will be an AP entry into DCA, and it's nice to know that when I get hungry, I will have a few places to choose from.
Disneyland Here I Come Again! October 1, to October 6, 2015
My husband and I always get the Countdown Chicken Fusili and usually share. It's yummy and filling. If not there, we go to Plaza Inn and share something. I eat like a bird, though, so this might not work for everyone.