Considering the actual degree doesn't make a huge amount of impact (depending on what you want to do), I'd recommend looking at ROTC with a degree that interests you, but isn't too challenging. In most cases, the grades matter more than the degree. For pilots, for example, the ASTB and the GPA are two of the biggest factors. Choice of degree matters for certain applications, such as becoming a test pilot later, but for commissioning, you could get a degree in underwater basket weaving and be picked up no sweat.
I'm sure there are more examples than the two I can remember offhand, but two of the most successful pilots I've seen around my year group received a Naval Architecture degree and a Political Science degree. It makes me really glad I didn't go Aero Eng.
As far as ROTC vs. OCS, the only thing OCS really buys you is a guaranteed slot in the job you want (unless you medically DQ). ROTC gets you a free college degree. Make of that what you will. Might be worth discussing with some people currently at ROTC how often people get their top picks if that makes any difference to you.