Definitely don't go the recon MOS route. If for whatever reason you don't make it through, you will be given a random MOS. Go 03 then recon if you want the grunt life. Also, my personal advice, and some will disagree with me on this, is to not worry about an MOS that "will transfer" once you leave the Corps. Instead, choose an MOS that will be something you'll likely enjoy doing and use the educational benefits the military provides to set yourself up. Take all of the college classes you can while AD, then when you get out, use the GI bill to finish the classes you have remaining to get your degree. Even if you end up choosing an MOS in a field you'll find a civ job in, getting a college degree will only help you stand out from other applicants and lead to you making more money. Another thing about choosing an MOS that you feel you would enjoy doing, is that it may lead to you deciding to make a career of out being a Marine, and there's not a damn thing wrong with that. Not many other opportunities in life will allow you to be in your 30s or 40s and get paid to simply breathe for the rest of your life.