Here is a velocity curve that I use with my Roland Juno DS88, on the heavy "key touch" setting. It gives me everything from super quiet to fortissimo.

Of course it is based off of my playing style, but should provide decent enough results right across the board.

Velocity = [1, 15, 24, 32, 45, 63, 79, 90, 105, 127; 2, 4, 9, 27, 44, 75, 100, 119, 127, 127]

Nice! I also have the Juno DS88 and this is the velocity curve I use most of the time in case it helps anyone:

Velocity = [0, 1, 16, 30, 69, 119, 127; 0, 0, 32, 64, 96, 127, 127]

Of course it is based off of my playing style, but should provide decent enough results right across the board.

Velocity = [1, 15, 24, 32, 45, 63, 79, 90, 105, 127; 2, 4, 9, 27, 44, 75, 100, 119, 127, 127]