The Githyanki can be a great choice for the story. Their backstory is deeply intertwined with the lore of the game. They have a long - standing history and their own goals and motives which can lead to some very interesting story arcs.
I'd say the Drow can be a good race for the story too. Drow come from a matriarchal and rather cut - throat society underground. Their presence on the surface in Baldur's Gate 3 can lead to all kinds of interesting story developments. They have to deal with the prejudices of the surface - dwellers while also having their own internal struggles related to their drow heritage, which can make for a very immersive story experience.
Half - Elves. They have the best of both worlds. Their human side gives them a connection to the shorter - lived, more chaotic races, while their elven side provides them with a touch of the magical and the long - lived. This duality can create some really interesting internal and external conflicts within the story. For example, they might struggle with their place in both human and elven society, which can lead to great character - driven storylines.
The Half - Elves. They are a blend of two races, and this often leads to a sense of not fully belonging anywhere. In the story of Baldur's Gate 3, this can be explored in many ways. For example, they might have to choose between the cultures of their human and elven sides, or they could be shunned by both. This inner conflict and the search for identity can create a very engaging story as you progress through the game.
The Paladin class is also excellent for the story. Paladins are knights in shining armor, literally. They are bound by a strict code of honor. This code often leads them into moral dilemmas and complex story situations in Baldur's Gate 3. Their combat prowess combined with their sense of justice makes them a force to be reckoned with and adds depth to the story as they strive to uphold their values.
Astarion is one of the best. His complex backstory as a vampire spawn is deeply intertwined with the main plot's themes of power, corruption, and redemption. Gale is also great. His connection to the magic and his quest for power and self - discovery add a lot to the story. Shadowheart's mystery and her own journey of faith make her an interesting companion for the story as well.
The Githyanki origin story is great too. You are part of this warrior race with a rich history and culture. It gives you a different perspective on the game world. You have unique abilities and interactions based on your Githyanki heritage. For example, your connection to Vlaakith and the whole Githyanki society can lead to some interesting storylines and interactions with other characters who may be in awe or fear of your race.
A good build could be a Sorcerer. Sorcerers have powerful spellcasting abilities from the start. Their innate magic allows for flexible combat and interaction in the story. For example, being able to quickly cast fire spells to deal with groups of enemies or charm spells to influence NPCs during important story events.
The best class for the story in Baldur's Gate can be the Bard. Bards are great storytellers themselves and fit well into the narrative. They can use their charm and persuasion skills to interact with various characters, and their musical abilities can add a unique flavor to the story. They also have a good mix of combat and non - combat abilities, making them versatile in different story situations.
In my opinion, a great party story often involves the diverse character interactions. For example, the story of a group consisting of a mage, a fighter, a thief, and a cleric. The mage might accidentally set off some magical traps while exploring dungeons, and the fighter has to protect the party from the ensuing chaos. The thief could then use their skills to disarm the remaining traps, and the cleric heals any wounds. This kind of cooperation and the little mishaps along the way make for a great party story.
Astarion is a great companion for the story. His complex backstory as a vampire spawn adds a lot of depth. He has his own motives and secrets that unfold as you progress in the game. Another good one is Shadowheart. Her religious beliefs and the mystery surrounding her true nature make her an interesting part of the story. And Gale is also quite good. His knowledge of magic and his personal quest related to a powerful artefact tie in well with the overall narrative.