Hello!
I haven’t played as a hunter in a really long time and im feeling that I want a hunter at 120 so im leveling one right now.
When im leveling I am bm cuz I like that you have pets and the rotation but I kinda also want to play marksman. I like them both and there is some things that I like more with bm and same with mm.
What spec is best on what, what is preferd in arena and dungeons/raids.
also what do you think is the more fun spec and why
appreciate all help 
bm is the best
No knowledge in PvP as I gave up on taking that seriously since Legion.
For PvE BM is best… you should, however, try both and see what you have the most fun playing, I like BM better but fun is different for everyone.
Key difference in the feel of the specs is that you can be the loner ranger as Marksmanship, while as BM pets play a big role.
They are both fun to play. I think Mm has more damage than BM. Well mobs seem to die slightly quicker with MM. I enjoy to play BM more though. I like the pets
Survival is the best leveling spec for both outdoors and dungeons. 
Just play what you find fun.
Since the hunter is an alt that I don’t want to put too much effort in and be useful in a mythic raid environment, I went for BM. Despite being less fun than MM, the rotation is more forgiving to mistakes and the damage output is comparable while maintaining more freedom of movement.
So it depends.
My choice would be SV or MM if the hunter is main because of the fun factor.
BM if the hunter is supposed to be an alt with maximum usefulness in a raid
BM with the lvl 15 talent for another pet is fun. I like seeing two matching pets out at the same time for some reason. It’s not twice the damage (120% instead) but it works well for me.
Personally i prefer MM because i like big numbers and aimed shot, sadly this expansion’s iteration is pretty bad. Both specs have very little variation on their talents in pve, pvp is pretty unplayable if you are MM, BM is decent in pvp. In dungeons and raids they are both competitive, but BM is better because of mobility/utility, still the difference only comes if you want to push mythic raiding and high M+, if you are not interested in this two both of them are good.
MM is way more static as you will be casting aimed shot a lot and it’s a 2.5 sec cast time with 2 charges, still a lot more mobile then most ranged specs.
BM is completely mobile and doesn’t need to cast anything standing still.
Personally i think both of them are kinda dull this expansion, but that seems to be a trend.
TL;DR If you don’t push high end content go for the one you like, BM very mobile, MM mobile. Both bit dull, still fun imo. Middle of the pack dps. MM dead in pvp, BM decent in pvp.
In Eternal Palace there seems to be very little difference between MM and BM
https://www.warcraftlogs.com/zone/statistics/23
Mythic Plus Dungeons it seems BM has the edge
https://www.warcraftlogs.com/zone/statistics/20
I have a feeling for Arena it will be Survival Hunter
And not survival ? 
survival in pve is kinda dead since the start of the expansion, it’s basically only played in arena and it’s prolly because it’s the only good pvp hunter spec.
All hunter specs are relatively close - even survival. Heck survival single target damage is easily comparable to the one of BM (if not even better, not sure of this yet). But problem is that there are very little survival hunter logs to pull equally thorough statistic vs other 2 specs. For example for my surprise other week-end, there was only 1600 (!) survival hunter Azshara logs. And in mythic was like 7 ? And those 7 likely are off-specs.
or when we look at HC comparison :
Overall I feel each spec has their own strong sides, but they all feel and play very different. for example I love survival a lot, but I despise modern MM a lot.
It is dead not due damage, but it being melee, and in mythic raid for example there are mechanics that require ranged dps (i.e. stand alone etc). Damage and performance wise survival is far from dead.
Also most people, who roll hunter do it because they liked ranged. Survival ‘mains’ (here I mean as main spec, she is not my main character) are either vanilla survival hunters who have nostalgia (i.e. me ) or have rolled hunter purely for melee (I know some). Otherwise it being melee puts people off.
Yeah, it’s not a damage problem, people just either don’t like melee, don’t like the spec or their groups have no space for another melee. The damage problem is more in arena then anywhere else for hunter rn, but even ther it’s not even really a damage problem.
Marksman is scaled better than Beast mastery and can pull relatively better numbers, but requires more complex management, since beast master have all his skills exclusively instant cast, meaning as marskman you have to stand still for your aim shots, while BM can be on the run all the time.
If you are fine with planning ahead to stand out of danger while casting (basically caster mentality) go marskman, it is pretty rewarding,
If you have no clue what you are doing (like majority of hunter players anyway) go BM and you can still be viable.
Also if you are hipster and want to out dps everyone on single target, go survival.
Also another issue I feel is rotation. It is a bit more demanding rotation vs i.e. BM or MM. It is very nice in bfA (was bad in legion), but there’s already a stigma attached to it. Otherwise the modern rotation is relatively fluid and super fun. If people like melee, i would recommend people try survival hunter out as it is probably best thing I ever did in BfA.
There’s also the gearing issue. To get good out of your little survival, you must stack enormous amount of haste, and once you got all that haste, then you need versa; which means you cannot use your MM/BM gear anyway, and so many hunter may swap between MM/BM, but leave survival be on aside.
This isnt true. MM and Survival are much closer stat wise (haste + vers) than BM, who just needs crit.
Meh don’t find the rotation demanding in single target at least, like 99% of the specs right now you have a very simple priority list you follow as closely as possible.
Honestly don’t find the rotation fluid, the gcd being that of a caster class even if it’s melee kinda bothers me, the rng on kill command makes no sense and having no choice on what to spend focus on makes the rotation not very good imo. can still be pretty fun if you stacka lot of haste as you say and you go with double charges on kill command, but that’s a bit too much effort just to strat playing a spec. Honestly i really hope next expansion they change the one that designed hunters this last two, because they are very high, and seemingly haven’t stopped being high all the expansion seeing the complete lack of tuning on our talents in general.
for arena BM as well
Ah I’ve been misinformed then! Or just recalled wrong while writing. I stand corrected 
You see my hunter was BM before respec and was abandoned in S1, and it was just recently due to forums here I decided to conduct an experiment.
In M+ when you use the bombs talent, you have to pay attention what bomb you use and cannot spam it. You can get ok aoe by spamming too, but you can pull pretty numbers when you pay attention what type of bombs you throw, which for me is a bit more demanding than dealing with M+ as other specs. Since bombing is your major aoe, so you rotate between bleed aoe (KC), cleave, and what type the 3rd one was again … anyway you have 3 bomb types with the talent.
In raid I got some 85%- 95% logs on my 1st HC EP raid, so the bird of pray rotation must be much simpler from M+ aoe one as with last i do struggle a bit to get the maximum potential out yet . True.
Survival hunter has 3 different DoTs, increasing burst with main spender that must be done correctly, enormous mobility and adaptation to various situations, incluiding being out of range, which makes it one of the most versatile melee classes in the game as off now.
It is also class with great potential to burst out icnredible numbers if played properly or being constantly on rock bottom, if played poorly.
Which is probably the reason why you dislike it. Cant blame yaBM and MM are faceroll both.