LabVIEW.
Ditto.
Another vote for LabVIEW.
LabVIEW would definately be up towards the top.
It is the best designed platform for pure object oriented programming.
The only drawback with LabVIEW lays in non National Instrument equipment. For some of these the manufacturer will provide a .dll for creating CLFs to code in their equipment, but they tend to not be very robust. Often you are left with having to redesign the driver for the instrument yourself.
However, for most common instrumentation (Tektronix, Agilent, ect.) there already exists very well constructed vi's for them that can be modified to tailor it to the application.
LabVIEW...agreed!!!