Ok, I would consider myself a boss when it comes to bringing meals into the parks. The fact that I cook 90 percent of our meals for 2 weeks every summer is one of the main reasons I've been able to bring my girls every year. I have an Igloo Maxcold soft sided cooler that is amazing at keeping things cold
http://www.ebags.com/hproduct/igloo...isttype=spla&gclid=CMHa-tbirNICFUSBswodH2YDxQ I've been using the same cooler for 5 or 6 years now. I love how it has the mesh top where I keep fruits, individual baggies with each kids daily snacks (small chips, laughing cow cheese, rice crispy treat, etc) and anything I don't want to get crushed. In the belly of it I pack our main meals, I can get quite a bit in it. There is also a nice zipper pouch on the outside where I store condiments that don't need to be kept cool-salt, pepper, parm cheese/ketchup/mustard/mayo/dressing packs, extra napkins and plastic ware, hand wipes.
As for the types of meals I make and bring in: Regular sandwiches, bagel sandwiches, bagel with peanut butter, pasta salad (I make a huge pot day one and bring a container of it everyday as a snack or meal), hot pizza if I cook it right before we leave for the parks (i'll wrap it in tin foil) or we love cold pizza too, chicken ceasar wraps, chicken ceasar salad (I buy frozen boneless chicken breasts and make a bunch at a time, usually while I'm winding down at night and then cut them up and leave them in the fridge to use for whatever), breaded chicken patty sandwiches, cheeseburgers (wrap in tin foil and eat for lunch so they are the warmest) or we eat them on a day that we leave late for the parks, hot dogs (I pack the hot dogs in a tupperware container and then get 2 cups of hot water from quick service, dump them in the container, cover it and I even then wrap a piece of tinfoil around it. The hot water will steam cook the hot dogs in about 10 mins. I carry the buns sometimes in the package and it'll fit on top of all the food or I pack them 2 to a plastic baggie), pasta (I pre cook the pasta plain and then put it in a tupperware container, I get one cup of hot water from counter service and dump in in the container, seal the container and swish the hot water around to heat up the plain pasta. In small plastic containers I bring alfredo and red sauce (one kid will only do alfredo the other red) and then I drain the water from the container back into the cup and dish out the pasta to each kid with their choice of sauce), cold fried chicken is always a winner too, I do mac and cheese and pack them in thermos containers, soup in thermos containers, etc. Since we are there two weeks we usually repeat most meals two to three times but I was able to do 11 to 12 days worth of meals and snacks for about $200.