What Ice Chests Do You Carry

I have a cheapo Iglo that I bought at Wallmart based on low price. We have used it for a couple of years on trips cross country in our truck, but it does not keep ice from melting 70% away by the days end. Was looking in Wallmart at the Coleman that say they are guaranteed to keep stuff cool for 5 days and a smaller one for 3 days. The clerk recommended them. The five day one was a little bigger than I wanted, but if it is much better I would get it.

Now I don't know what that translates for Ice not melting as fast. I wanted something that we could possibly keep ice in for longer periods of time. What have your experiences with Ice Chests been? Have you found one brand superior to others? Also how large a one do you have. They are by gallon size I think.