Does one US military branch think it's superior?

Of course, selecting a branch is a very personal choice with very different experiences and advantages/disadvantages. As an Air Force junior enlisted serving alongside a "Joint" really Navy intelligence organization I had a easier time working with the Navy Commander than the Master Chief... Tradition. I was the SSIO no one touched a computer with my signoff, making MSgt made my job easier. I had opportunities to work with Army and Marine Intelligence as well, they tended to get promoted to Mr. Warrant that is, always incredibly professional. I believe mine was the best choice though.

Im not in the Military but many of my friends are and each one will swear up and down, all day and night that their service branch is superior. I think it boils down to pride more so than logical reasoning, thats just my opinion though.

I do believe there is quite a bit of inter-service rivalry even to this day. A prime example of this are the various camouflage uniforms our Armed Forces are sporting. Instead of having everyone switch to the Multicam or Woodland/Desert Digital patterns every branch came up with their own ideas. Whether or not they think they are superior depends on the topic I think.

Being penultimate to the Navy is very important. Let's keep trying folks. :))

Yes there always has been, I always see it going on between army and marines, army and air force , nave and army, coast guard and army , it will go on like that as long as we are alive unless something in our nature drastically changes.

We all give each other crap because our branch is our team, but when rubber meets the road we all back one another......

Except the Coast Guard..... Forget those puddle pirates.......

This reminds me of a conversation I had with an Army vet in college. We'd both been enlisted at just about the same time:
Me: "Hey man, I gotta ask ya something. We hear a lot of heresay about the Army, but do you guys really qualify on electronic targets that tell you where you hit?"
Him: *looking very perplexed at the question* "Yeah, at least my unit did, why?"
Me: "Oh, in the Marines we split the range detail in half and take turns manually pushing the targets up in a frame down-range."
Him: *stares* "You Marines are f-----in CRAZY!"

Here's the skinny of it....I was in the Army Reserve at age 17, I went to basic training at Ft Jackson SC I later enlisted in the Marines Active duty and went to bootcamp in San Diego L Co PLT 3089....I later returned to the army on active duty (not because I didnt love my beloved Marine Corps but because the closings and downsizing that Bill (Clown) Clinton was conducting at that time. I couldnt return to the Marines because at that time prior service marines couldnt return to the marines no matter what your re-entry code on your DD214 said)
I have said all that to show you that I know where I am coming from....Im speaking from experience- Marines Bootcamp is hands down one of the toughest things I have gone through in my life...army basic: mmmmm not so much. There are plenty of soldiers that say "hell no, I didnt want to join the marines cuz those suckers are crazy". That tells you in their heart they know who is the hardest, meanest, and most gun-ho!! Now lets be honest about the air force and navy: air force is like a big corporation where people were uniforms lol they go around calling themselves by their first name lol they are almost not a branch of the service lol (I was stationed at an air force base- I saw it first hand) and now for the navy- aside from seals and seabees (seabees arent super hardcore but they are extremely dedicated to their mission) what does the navy have? so....in my humble opinion- The Marines is the better branch, second to none! Semper Fi!!
I know we are all part of the same team- I know we depend on each other, I know all that jazz...but Im just saying... (my opinion was not meant to insult anyone or hurt anybody's feelings....it is simply one man's opinion) In today's world where everybody gets offended for smallest thing I had to throw in that disclaimer

In my opinion:

Inner service rivalry is good when it: spurs esprit de corps, challenges troops on their training, builds confidence and motivation, allows for troops to excel and work together...

It should be avoided at all costs when: there is unjustified Rhetoric, when individualistic opinions hurt other service members, when competition leads to violence, abuse, and hate towards other service members...

Remember, competition done right leads to excellence, however when done wrong, it leads to disdain and unjustified hate and ignorance. Leaders take note!

Inner service rivalry is a great thing to push our troops to be better at what they do. However, at the end of the day we all know we are on the same team. My branch is superior, should be the answer to your question from all service members. If you don't think your branch is the best, you may be in the wrong line of work.