A lot was changed from 11.04 to 11.10. The biggest change was that classic Gnome was removed as a fallback option to Unity. Also, PiTiVi was removed as a video editor and not replaced. Thunderbird was put in place of Evolution.
Of course, these were only removed from the default disk, not from the repositories, so "the most complete set of applications" doesn't really make sense as a question.
For example, if you got an 11.04 Ubuntu disk, you'd get a copy of PiTiVi with it. But then there would be updates to get it to the latest version which you'd want to download. You might as well have got 11.10, and done "apt-get install pitivi" to start with!