When I was in the 8th grade, I was riding in a small plane with my parents and we landed at the wrong airport in the dark. Instead of the city airport, we landed on an Air Force base where a jet was doing touch and go landings. That could have gotten bad really quickly.
It's pretty unusual for a major commercial flight to land unintentionally at the wrong airport.
I've seen some pretty bad landings on commercial aircraft, but never landed at the wrong airport in one. On one occasion when we were landing in New Orleans we had the smoothest landing I've ever encountered on anything, even a helicopter. After we landed, nearly everyone applauded. They didn't realize that to make a landing that smooth, we floated a long way down the runway before actually touching down. It would have been really easy to run out of runway. Consequently, what they saw as a good landing actually approached being a dangerous landing. I hope that pilot eventually learned to plant the airplane solidly on the ground and bring it to a stop long before reaching the end of the runway.
That wasn't the most dangerous landing I've seen on a commercial aircraft. Flying into Houston Hobby once, we did a touch and go -- something you never see on a commercial flight. I don't know if any other passengers realized why we did a touch and go, but as we were landing another airliner was taking off on an intersecting runway. If we had tried to stop, there could have been hundreds of dead. As it was, it crossed the runway intersection just a few seconds after we passed it.