New apps would be great, whether it be games, utils or other. Updated networkrelated sofware (I am still eagerly awaiting IMAP-support in YAM) is very high on my list.
For games, I wouldn't mind larger (non-floppydisk based) games with highly improved graphics. I'm dreaming of high resolution versions of graphical adventures such as Day of the tentacle, Monkey Island or The Pawn, supporting external midi sound modules...
Common apps often support higher specced Amigas, but games commonly only support the lowest common denominator and thus hardly make use of faster processors, more memory, large harddrives, flicker fixers and so on.
And yes, I would most likely pay for software like that, if it was a real improvement over existing software.