If you don't mind spending your summer on a ship - go to USNA.
JAM, you seem to think the Marine Corps and the Navy are diametrically opposed. Not true. Marines typically deploy on Naval vessels, which are a tactical part of their battle plans.
Look at the promotion rate for field grade officers. It may not matter for a 2nt, but later on, familiarity with ships and their capabilities becomes invaluable.
I hear that USNA is imposing a "quota" on Liberal Arts majors. One might attend intending to major in Poli Sci and end up in Ocean Engineering.
Thanks for the replies. It is helpful. I went to both SLS. I am a very strong candidate for both. My one concern is if I choose USNA and then don't get to choose marines. What are the odds of that?