You don't want the full list because it's gigantic, but quoting the official Emacs homepage, here are the most important ones:
Emacs version 22 includes GTK+ toolkit support, enhanced mouse support, a new keyboard macro system, improved Unicode support, and drag-and-drop operation on X, plus many new modes and packages including a graphical user interface to GDB, Python mode, the mathematical tool Calc, the remote file editing system Tramp, and more.
I still hate it :D