What are the best branches for Army Officers and why?

You may want to consider commissioned life after active duty - that is if you join the Army Reserve or National Guard. MI is a very strong branch for having "tour" opportunities as a reservist, while any combat arms branch should serve you well in the National Guard. Good luck and thank you for your service!

Love my branch because of the diversity we have. Geospatial, General (Horizontal, Vertical, and Bridging), Combat (Sappers, Route Clearance, Mobility Augmentation). Bottom line you could be an Engineer Officer your whole career and never do everything.

Infantry, MI, Engineer

Whatever branch I chose was the best, of course. :-)
I think you would be better off to ask one officer with experience in each branch what are the pros and cons of that branch, and especially ask what they actually do in that branch. You are sure to hear from some that a combat arm is the way to fastest and furthest promotions, but that ain't necessarily so. It may also help you to know that some branches, like MI have a Christmas tree shape, with few requirements for Lieutenants but lots and lots of requirements for Captains and above. Half of the officers in my MI Officer Advanced Course (I believe that name is obsolete?), including me, were Infantry first and transferred to MI as O-2 (P) and O-3.

Infantry is the largest, therefore there are more officer slots and places to go all over the world.

I was a Field Artillery Soldier’ branch transferred to Logistics with the major draw down following Desrt Storm. Field Artlliery is being reinvented and is a growing branch. I spent a lot of field time (thus the first word in the name of the branch)’ lots of DS support to the infantry, worked with several armies around the world, making FA a great branch protected by St Barbara. As cannon tubes fell out of vogue, I found myself doing Logistics cause I understood how to support the warfighter - what they needed when they need it and where, a valuable lesson learned from delivering supporting fires. FA has more to offer than meets the eye making it one of the most competitive branches in the Army.

PO3-First off, congrats for starting the journey of commissioned service. Mama Navy will miss you, but I can't say you're not making a wise choice in considering a wider field of play.

Here's my advice, for what it's worth: You placed Infantry FIRST in line...that tells me something about why you're considering this path. You're also a GM, which tells me more. Ask yourself what's motivating you to become an officer in the first place. If I had it to do all over again, I'd have opted to go into the Army or Marine Corps, and fight for all I was worth to be an Infantry officer while I was young and "invincible". Why? Because when it's all said and done, that seems to be the basis for moving up to some bigger, more challenging things in both services. One has the shot at becoming the elite...or if nothing else, a member of one of the highest respected warfighting communities in the Military.

In general, the thing I regret (honestly, deeply) the most about my short military career, is that I was so myopic at say 17-20 on becoming an Aviator-that made a great many decisions for me that were not tailored to my core competencies, desires, or passions. Ultimately, I spent what was left of that career trying to play "catch up", and pursing goals that my parent service had fewer options for.