For me, it would to be Macready, Deacon, Dogmeat, Paladin Danse, and Piper.

Macready gets extra points cause he was the mayor of Little Lamplight in FO3. He is also really cool. He has the merc atitude, but is not gonna ANYTHING for money. He has morals.

Deacon has a lot of quirks about him that are really cool. He can randomly change into different outfits to blend in. He is also a good sneaking buddy. He also reminds me a lot of the Vincent Vincent companion mod for FNV...just less coo coo and less hopped up on drugs.

Dogmeat is a lot more fleshed out this time and has a lot of helpful abilities. He can sniff out anything for you, so when you're searching for loot, or just want to know if there is any enemies nearby, he is very useful. He can also hold onto enemies(not all I think) so you can get a better shot at killing them. He is also just SO CUTE! Another cool thing is that he will love endlessly no matter what actions you do... unlike some companions...*cough Strong cough cough*

Paladin Danse is a pretty cool soldier when you first meet him. He seems like a standard BoS soldier ready to fight for what he believes in, but when you get to know better, he is a great character, especially at that one big event,

Spoiler:

 

When it was revealed that he was a synth, my mouth literally dropped. Kudos to Bethesda for making my mind explode for a couple of minutes

. He is also a absolute beast in combat.

Piper is an awesome character. She is very quirky and heartfelt. She is the love interest for my character. She also gives sweetrolls, so that's extra points for me.


My least favorite companion would have to be Preston, and the thing is, I don't even hate him the slightest bit. He is actually a pretty cool character. It is just that out of all the companions, he seems to be my least favored.

You seem to have gotten around to a lot of the companions already.  Nice work.  I've only been able to try out Dogmeat, Piper, Curie and Cait (sp?).  Like you said, Preston seems decent enough, but I'm just not interested.  I passed up Danse.  He's a bit too hardcore for me. The "Do what I say, when I say, no questions" attitude is a bit much.  Deacon seems alright.

The thing is, Dogmeat is the most useful companion.  I also love that he has no negative responses to my actions.  Cait and Curie had something to say about almost everything I did.  It was annoying.  

Piper is my favorite.  Though, she's tough if you decide to deviate from a hero's path.  She's awesome though.  Dogmeat comes in second place.  Only thing I don't like about the dog is the excessive whining.  The high pitch sound gets old fast.

Down the road I hope to try out all companions, just to see how it is.

@Pickpox111

I can tell that you dislike Dogmeat.

Dogmeat is an ass:

 

Favorite: Cait. She's got a hell of a personality, has the funniest sayings out of all the companions and is one tough cookie. She takes a lot of beating before going down.

Least Favorite: Toss-up between Dogmeat, Curie

Spoiler:

 

(prior to changing)

and Codsworth. No matter what I do these three seem to pick the worst time to move in front of me. My character has been killed or seriously injured because of these idiots.

I love Curie. She's cute, especially combined with the French accent.

Least favorite? If I have to make one I'd say Strong. I don't really hate the dude I just don't find him interesting.

I like Nick Valentine as my favorite companion for his personality,story and morals.

My least favorite companion is Strong. I don't find him interesting and he dislike everything I do in the game.

Curie has the only voice I like but

Spoiler:

 

I hated walking with her before she changed

definitely macready. i was so surprised when he said he was the mayor of little lamplight...i was like "WTF, that little punk grew up this much!?".

I've only really used dogmeat, curie and codsworth and I gotta say I like them all.

Although I had to shake my head and giggle when I had codsworth and we were attacked by you guai

"It's almost unbearable"

My 3 favorites so far are Piper, Valentine, and Macready. Haven't run into Cait or Curie yet, though I have discovered the locations they are in I just haven't gone into them yet, so can't determine if I'd like either of them yet. Codsworth and Dogmeat are ok companions for me, though I feel as though I'd like Dogmeat more if he wasn't constantly running all over the place.

Least favorite thus far is Strong. Don't get me wrong he's kinda funny with some of the things he says and he's tough but....disliking it when I pick locks? That's annoying.

I love doge meat. Such apocalypse. Much fallout. Wow

I don't own the game (need to buy a complete PC to be able to run it), but from watching AlChestBreach's videos religiously (who doesn't?) I gotta say Valentine so far. he hasn't found Curie yet and doesn't work with Strong, and some others, so I don't know much about them.

Valentine's story has progressed the most during his playthrough, and he seems really gritty and interesting. Know a bit about Curie's story from reading about it online, so would be nice to see it happen sometime in the future...

for me was Cass but i just dont play with companions cuz i want to be more hard and the enemies wont focus fire on them but reather me and thats why i go (han) solo

If we talking about vanilla, its Cass, definitely.

I really like pretty much all the companions, but I don't really use dogmeat (I like being able to get feedback) and strong bugs me

Not considering their perk or combat plusses just their interactiveness - Cait, Curie, Nick & Macready are the companions I like best to have around. Good, humourous & pleasant personalities with good dialogues. Strong is the worst. His negativity just wore me down. & I'm not sure if it's a bug at my end but he comments more frequently compared to the others, which makes him more annoying.

i have to agree with you both strong is awful . He dislikes power armor which i use a lot and has a lot of annoying dialogue. My favorite is X6-88 he holds up well in a fight and fits with my character.

I like Piper the most, while I hate Strong. Honorable mention goes to Preston, who just annoys me.

If I had to pick a favorite Companion from each game it would go like this:
Fallout 1- None [traveled alone]
Fallout 2- None [traveled alone]
Fallout 3- Fawkes
Fallout NV- Boone, then Cass
Fallout 4- Piper, then Nick

as for least favorite
Star Paladin Cross (3), Lily (NV), X6-88 (4)