All of the DL flights (and all of the other carriers, too) offer IFE (in-flight entertainment) on trans-Atlantic flights. I suspect you are looking for seatback entertainment or personal TVs. Many airlines offer personal TVs on some of their US-Europe flights, but most of the US carriers do not have PTV on all of their flights.

Flights to Europe are relatively short, though, and you should be okay with a book, Ipod, laptop, or the movies from the overhead TV displays.