Most trees except mulberries require spraying, you can get by without, as long as you don't mind insect damage.
Blueberries usually are disease free, but are not easy to grow if conditions cannot be met (moist and acidic soil).
The earliest fruit would probably be strawberries. Raspberries and blackberries usually are disease free too, but with the new fruit fly, all these fruit may require spraying in the near future., if not already.

This post was edited by Drew51 on Thu, Jun 19, 14 at 19:08

Mulberries and blueberries are the first two fruits that come to mind for me. Native persimmons are another thought. Of the fruits you mentioned, gooseberries might be comparably easy. I suspect plums would be very difficult. I'm sure apples wouldn't be nearly as easy mulberries/gooseberries/blueberries/persimmons. I wouldn't call hardy kiwis or pawpaws easy fruits to grow, but they don't really have disease or pest issues, so you could probably grow them about as easily as anyone. Figs likewise would simply present over-wintering challenges. Check out Trees of Joy in Pennsylvania if you're thinking about growing figs.

Pawpaws, persimmons and mulberries for tree fruit. Blackberries and raspberries are easy too.