Ignoring film for the moment, if you are interested in printing big then you are better served with a bigger sensor.
However, if you are perfectly happy with 8x10 or whole plate contact prints (Edward Weston style) then you are well served with just about any digital sensor currently manufactured.
Sharpness is a function of software when dealing with digital sensors and is really not the primary reason to use a larger sensor.
From the film side I think the discussion regarding the value of size has pretty well been settled way before I was even born.
You gotta love a fast lens;
It is almost as good as a fast horse!