Fighter

Arcane Archer

Source: Xanathar's Guide to Everything

An Arcane Archer studies a unique elven method of archery that weaves magic into attacks to produce supernatural effects.
Arcane Archers are some of their most elite warriors among the elves. They stand watch over the fringes of elven domains, keeping a keen eye out for trespassers and using magic-infused arrows to defeat monsters and invaders before they can reach elven settlements. Over the centuries, the methods of these elf archers have been learned by members of other races who can also balance arcane aptitude with archery

Player Story Tips & Ideas Arcane Archers in Felwind are considered master's in their chosen fighting form. Normally some of the most expensive fighters to hire for their talents. They will often be well disciplined and well spoken. Their weapon of choice has normally been with them for a good part of their life and may be rather protective of it. They can be show-offs at times and are normally easy to challenge to contest of skill.

What to Expect Players can expect A magical archer. based around ranged attacks made with bows or crossbows and infusing those attacks with magical effects.
some unique special skill shots, some generic buffs as well as some tools filling the vibe of a hunter or ranger. though its simple on paper its highly effective and offers alot more 'Bow Skills' vibe than what you might expect from a Ranger. those dedicated to this sub-class will get huge mileage out of it.

What would DM Darwin Change? 'Arcane Shot' Allow this to be used multiple times not just once per turn. Imagine being a magic archer but only one of your three arrows are magic?
'Curving Shot' Allow the reroll to apply on the same target ONLY when there is only one Foe. Such as a single major boss or the last one standing of a group.

Banneret

Source: Sword Coast Adventurer's Guide

A banneret is a knight who inspires greatness in others by committing brave deeds in battle. The mere presence of one in a hamlet is enough to cause some orcs and bandits to seek easier prey. A lone banneret is a skilled warrior, but a banneret leading a band of allies can transform even the most poorly equipped militia into a ferocious war band.
A banneret prefers to lead through deeds, not words. As a banneret spearheads an attack, their actions can awaken reserves of courage and conviction in allies that they never suspected they had.

Player Story Tips & Ideas text

What to Expect A subclass built around supporting your allies as well as yourself with the use of your normal fighter skills. very leadership role with the vibes of creating good moral and keeping the party together. also has some stuff relating to strong persuasion skills to wow the masses with your inspiring call to arms.

What would DM Darwin Change? text

Battle Master

Source: Player's Handbook

Those who emulate the archetypal Battle Master employ martial techniques passed down through generations. To a Battle Master, combat is an academic field, sometimes including subjects beyond battle such as weapon-smithing and calligraphy. Not every fighter absorbs the lessons of history, theory, and artistry that are reflected in the Battle Master archetype, but those who do are well-rounded fighters of great skill and knowledge

Player Story Tips & Ideas Text

What to Expect Fighter with unique skills fuelled by a unique dice source. alot of cool special skills as well as some extra abelites relating to learning information about your foe's before combat begins.

What would DM Darwin Change? My main issue was 'Know your Enemy' being rather weak and situational, the 2024 revision made it much better but I would still have it be able to be used more than once per long rest.

2024 Revision Available
The main difference is 'Know your enemy' has been streamlined and improved.
'Relentless' has been changed to rather than granting you a free superiority die when you start combat at 0 it lets you roll a D8 in place of a superiority die to save its use at the cost of a lower possible max result. a overall buff indeed.

Bulwark

Source: Grim Hollow Pg 51

Cavalier

Source: Xanathar's Guide to Everything

Mounted combatant! very cool theme all around mounted combat. the cool thing is that your mount can be anything fantastical not just a normal horse. with the added benefit of team support as a sudo tank, drawing agro with a special mark punishing foes for targeting your allies while you are nearby.

Champion

Source: Player's Handbook

a rather simple subclass about improving your critical threshold and getting additional bonuses for saving throws and extra fighting styles. Its rather humble and straightforward approach I think is great amongst some of these other more complicated options. Really leaning into refining a few niche options. and fishing for crits can be rather effective if the DM offers the right weapons and equipment.

2024 Revision Available
The revision didn't change much, the biggest thing is now at mid levels you get an in-house luck point to reroll any of your dice once per turn really hammering home that main character energy. Finding a weapon that can further lower your critical threshold would be the build i think. Fishing for crits is simple on paper but mighty effective.

Commander

Source: Guide to Drakenhime Pg 159

Like the Barrent but more commanding your allies to grant them buffs and less people pleasing, more serious. Has some unique “Command Actions” they can do as a bonus action.

Echo Knight

Source: Explorer's Guide to Wildemount

a really cool subclass about making cones of yourself and fighting alongside them, but its not just about combat, your clones have a few scouting tricks up their incorporeal sleeves.

Eldritch Knight

Source: Player's Handbook

Similar flavor to a Hexblade Warlock but change all the warlock stuff for Fighter stuff. Gives access to wizard based spellcasting and that cool weapon bond skill as well as the ability to debuff foes on weapon attacks. pretty cool for a spell sword build that has a close to to a weapon or two

2024 Revision Available
a buff was given allowing the player to forgo an extra attack for a casting of a cantrip instead, paired with debuffing foes on a weapon hit its a pretty cool combo

Living Crucible

Source: Grim Hollow Pg 52

Psi Warrior

Source: Tasha's Cauldron of Everything

Psionic powered Fighter, similar to the battle master this subclass gets access to a unique resource in the form of a pool of D6 known as your 'psionic Die' Which are used to fuel special psionic abilities. this dice scales higher as you level up. give you offensive and defensive psionic abilities as well as some passive defense against psychic damage and easy cleanse of charmed/frightened conditions

2024 Revision Available
Reading it i don't think anything was changed aside from more clarification in the wording. that's fine its pretty strong sub-class already.

Rune Knight

Source: Tasha's Cauldron of Everything

Really cool Sub-class themed around the Joutunbrud (Giants) using their ancient forgotten Runic magic to give your fighter a bunch of unique elemental themed abilities. You get to grow in size gaining additionally buffs when you do and that ability scales with higher levels. imposing disadvantage on attackers and cool flavor skill proficiencies this class can be really good for Role play and character story development.

Samurai

Source: Xanathar's Guide to Everything

A Samurai, the king of doing one specific thing really well. I tend to hombrew Rappid strike to have no use restrictions casue I believe its cool and lets my players go absolutely ham on the 'One with the sword' trope. a really good weapon and other gear makes Samuria a really cool class to play without any spells. its rather straight foward when considered on paper. for those ultimate weebs who really wanna play that ronnin style character.

Shield-Bearer

Source: MCDM Arcadia Volume 20

On paper this has become one of my favorite subclasses. All about your shield with the ability to captian america throw it. bash enimes with it, shove foes around and take advantage of foes attackin allies with extra attacks or imposing yourself between your foes and allies. like the Samuria this class gets alot more milage with a good fancy shield and other equipment but i am very impressed. This Arcadia volume comes with several magic items and shield themed for the shield barer.

War Cook

Source: Dragon Stew, Pg 31

Has access to a handy amount of different magical cooking weapons with unique effects. can also cook dishes for yourself or party to provide buffs. and some features to give skill proficiencies. a very cheerful vibe with this subclass, you can play a serious cook who has left war behind to bring smiles to customers through food, or a young upstart looking to make it big in cooking but also needs to earn money through adventure. many ideas and all of them cool.

Witch-Blade

Source: Hexbound Pg 20

Has the uber cool ability to gain the 3rd level ability from any other Fighter Subclass once per long rest, has similar abilities relating to fighting style, making their weapons magical and other stuff but the 3rd level ability is cool enough I don't think I need to sell the subclass any further.