In a small cooler between my & DH's seats, we have a couple of bottles of water, a couple of cokes, some juice boxes or small bottles of juice like Sunny-D, & normally some kind of fruit like grapes. Since the cooler's small & will only hold so much, we have more drinks in the back of the van that we'll replenish our cooler w/ along the drive.
At my feet, I normally have a bag that contains snacks for the trip like Handi-snacks (those little packages w/ crackers & cheese that you spread w/ the little red sticks), fruit roll-ups & bags of those bite-size gummy fruit snacks, sunflower seeds for DH, oatmeal or chocolate chip cookies, & zip-lock bags of our special "road-trip" snack mix - which is snack mix that I make just for our road trips. LOL! It's not really all that special - just a mix of M & M's, Golden Graham cereal, Cheerios cereal, pretzels, dried fruit, & anything else I feel like including.
We stop in St. Augustine on our way to WDW for some "beach time" - last year, we stopped for 1 night on the way down & 1 night on the way back from WDW. This year, we're stopping for 3 nights on the way down & not stopping on the way back up. Anyway, our drive from TN to St. Augustine is normally about 7 & 1/2 hours. We leave around 4:30 am, stop for a picnic breakfast somewhere in southern GA at a rest area, and arrive in St. Augustine by lunch time, so we normally don't eat a lot of snacks on the way down. We probably eat more snacks on the drive home.
For our picnic breakfast, we have ham & biscuits, grapes, yogurt, juice, & coffee (for DH & me). I put a package of lunch meat ham in the cooler along w/ some small individual-size containers of yogurt. I bake some frozen biscuits in the oven before we leave home. When they come out of the oven, I wrap them in aluminum foil first & then wrap them in a towel before putting them in a basket. When we stop for breakfast, while they're not still hot, they're not cold yet either. This year, DH wants to pack small boxes of cereal along w/ some small cartons of milk too.
We also always have a thermos of coffee for DH & me! We gotta have our coffee!!