ROTC is a great officer producing program. Without spamming links, I'll just say there are avenues to obtain free education through every branch and component of the military. You have to choose what fits your interests and lifestyle. As @driz stated, there are very few INFORMED options about ROTC on the forums. @UltaPonch is an AFROTC grad and former AF pilot now Finance Officer. If you're lucky, he might make an appearance to provide AFROTC guidance.
Edit: OK, one link
ROTC allowed me to study Leeroy Jenkins for a living