Having spent almost 12 years in the service so far I would look very carefully at what you want out of the military. If you are going to use to springboard to something else like LE I would look at the Army or AF. With the Army you can sign a contract for a specific MOS...like Military Police. It might have changed but the Marines don't do that.
I have also worked with every service very closely. I've been in combat with everyone and the Marines are no better, in fact sometimes worse, that the 82nd, 101st, 10th Mnt in the Army. The Army gets a bad wrap b/c there are some many support people that the infantryman gets lost. I'm trying to be nice but the Marines are not all they are cracked up to be.
I will say the Marine marksmanship program is better than the Army's but for the most part that all evens out in a couple years. The average Marine isn't any better with a M16 than the average infantyman in the 82nd after 5 year.
If you think you are going to the Maries and getting jump out of planes and do a bunch a really cool stuff, think again. That is for the most part BS. It could happen but your chances are very slim.
Don't get fooled by the dress blues, that is the nicest thing the Marines have going for them. They have inferior equipment, an overblown sence of importance and are far more impressive in the movies