What are the best 35 Series MOSs for a possible career in the Intelligence Field?

At this point, any 35 series MOS requires a TS. So that really isn't a deciding factor. What do you want to do and what are you good at (or willing to get good at)? SIGINT is a lot of technical expertise and some maths, but also tends to be a bit more isolated. HUMINT is a lot of tactical expertise and some psychology, but also relies heavily on people skills. IMINT is a lot of analytical skills and interpretation, plus headaches from staring at screens. All source is a lot of analysis, some maths, some people skills, a lot of databasing and charting, plus a little bit of black magic. And even then it is slightly better than flipping a coin.

You mentioned on another reply that you were leaning toward HUMINT. Do you want to spend most of your time dealing with (and manipulating) other people? If yes, then great, HUMINT might be for you!

I would agree with SFC O'Malley. I spent 22 years as a 35F and one of the things is you get to know the strengths and weaknesses of each INT. A 35F is a jack of all ints and maybe a master of a few. Each single source person will tell you theirs is the best, but each is strong or weak based on the tactical, operational or strategic situation and the 35F has to weigh all that to provide a fused intel product.

Google the Army COOL (Credentialing Options Online) and it will break down each MOS and what different fields they can go into. Having been a 35M for over 14 years and a previous SIGINT guy, my money is on 35M. Fs are stuck inside a building without windows more often than not. Ls aren't actually intel. Ms get certifications a few of the alphabets are highly interested in and can get relevant experience in the states as well as deployed. If you want to be a M, you will do both tactical and strategic work if you stay in long enough as an active duty person but I don't know much about reserve/guard folks in this job. There ARE opportunities to support at least one of the alphabet agencies CONUS but sometimes those are hard to get. But, they are an option, you just have to try to get into one of their US field office as an active guy (ADOS orders for you probably) There are a lot of options available if you become a M, however, in all reality there are a lot of options any MOS you choose. It all depends on where your interests lie. If you don't like what you do, you'll be miserable the whole time so make sure you select something that is in line with your interests. If you have any other questions there are plenty of people here who can answer for you. Good luck!