I don't know of any successful ditching but I am open to be proven wrong.
As far as I am aware the manufactures all say that you can ditch and the aircraft will float but I want then to prove it.
Japan Airlines a DC8-62 flight 8032 on 22/11/68 hit San Francisco Bay 2.5 miles short of the runway.
No injuries to crew or pax, aircraft was fished out of the water after 55 hrs and was repaired and re-entered service.