We always hit up Costco when we get there. I did more "cooking" our first DVC villa trip but not since then. Now we do more frozen/refrigerated ready-to-bake type meals. We also eat differently than we do at home. It IS vacation, after all.
Pizzas
Costco has a great chicken pasta alfredo in their refrigerated section. Add a bagged salad.
We have also taken some refrigerated or frozen precooked chicken fajita type chicken and added that to bagged caesar salad.
Costco has some frozen angus cheeseburgers that are pretty good.
Frozen pot stickers are a great lunch or snack.
Macaroni & cheese (something we don't normally have at home, boxed mac & cheese, but it IS vacation!)
spaghetti & jarred sauce, again, bagged salad and loaf of garlic bread. This would be about the extent of my "cooking" on vacation.
BLT's (could even use precooked bacon)... again, about the extent of my "cooking" on vacation.
Frozen lasagna
Breakfasts are easy: Muffins, bagels & cream cheese, frozen breakfast sandwiches, could even do a big batch of breakfast burritos - crumbled sausage, scrambled eggs & cheese on tortillas. I prefer to TRY to have more protein in the mornings, so we will try to include stuff like this in addition to our muffins and bagels. We actually pick up a big thing of bagels and cream cheese from Panera on arrival also.
I will also second the comment about not buying too much. We have done this before. We drive so we can take SOME leftovers home, but since we do our drive home in two legs, we can't really take home refrigerated or frozen stuff.
We always have a villa (DVC). This trip in June we are actually doing half of our stay at OKW and half in a condo at Windsor Hills. So we always have a kitchen. I'm all about doing meals, snacks, etc in the villa/condo as much as possible to save money. But I also don't want to do a lot of "work" on vacation. So do pre-packaged/frozen/easy stuff. Also get a case of bottled water, soda if you drink it, wine, beer, snacks, etc. If going during warmer times, get snacks to take into the parks that won't melt (no chocolate, etc.)