RULE NUMBER 1---get everything in writing--MOS, Duty Station, bonus, everything!!!!!!
Seriously consider a job that you can use on the outside and follow rule 1(if you want to play with guns and run around in the woods, see below)
I was in the Corps, friends were in the air force and army. Marine boot camp is very tough compared to the army, and the airforce is really a college summer camp.
The best thing about the Corps is that after boot every body attends the first month of ITS, and is trained in small unit combat. After that, even if you run communications or fix airplanes, you still get to go out in the woods and play war every year or so.
Plus, riding Mike Boats and LCACs and traks rocks, and being on the navy boats isn't so bad when everyone sneaks on enough booze, and the boat stops in cool ports every few weeks.