Those two have better job markets, but OR has better funding possibilities. For OR, you can send your grant application to any mid-large corporation, promising to optimize one of their many messed up business processes and you get yourself a $50k on the spot.

Go to any decent campus and look around. OR people are usually older, with MBAs, and better healed financially. I worked for a few as a software developer (yeah, grad students who can afford to hire a software developer at market rates!)