Quad Cities - Bettendorf and Davenport in Iowa; Rock Island, Moline and East Moline in Illinois. I know 5 cities, but Midwesterners can't count... There is also The World's Largest Truck Stop just a bit away on I-80 in Iowa and tiny Le Clare Iowa close by which was amazing.
We camped twice there last summer on the Illinois side of the Mississippi River, once at Fishermans Corner which is a COE campground, and once at the county-owned RV park right next door to the COE campground. You camp right on the riverbank. Many campsites have a view of the dam there, so not only do you get to watch boats and barges go up and down the river, but also watch them make their way through the dam.
The COE campground takes reservations, and the campsites with the best river views fill up quickly. On both trips, there were plenty of spots available in the county RV park.
I recommend a week there, to include a weekend in the middle of that. People who can only stay for the weekend won't be left out. There are lots of things to do, besides watching the river.
So, which campground do we prefer? Hard to say. The county park has more sites with views of the river, but the COE has sites closer to the river. Both have electric and water, but no sewer. I was told the county did have a few FHU sites, but I can't confirm that. One caveat - COE showers have one on-off button for the water, and you can't control the temperature - the water is HOT.
So - anyone interested in Quad Cities?