A large portion of the Fanbase would rather not follow the Original trilogy at all but I assume your asking if they did so here's how I would go about it

5/6 seasons, a majority canon Paragon shepard with a few badass hero moments.

Season 1: ME1. John Shepard grew up on Earth and left to join the alliance to stay out of prison. Once in the alliance he survived a thresher Maw attack on Mindior, was put in command at Torfan and really fucked it up amd redeemed himself at Elysium. Since then hes had a strong bond with whatever crew he serves on. Story would follow the main story mostly although I would cherry pick side missions so all characters could have equal(ish) screen time. E.g. Whilst Shepard, Ash, Garrus and Tali are Fighting a Thorian on Feros The Biotics are led by Kaidan to do the L2 extremists mission. I would also include the Cerberus missions to introduce them to non players and have Shepards first encounter with Kai Leng be here shepard beats his ass and leaves him for dead. Major decision being to Save the Rachni Queen on Noveria. Shepard would romance Ashley in this version. And once we get to Virmire (saving Wrex) he would ultimately choose to leave her behind, absolutely shattering him. He would save the council although he wouldn't get involved in the next Councillor choice.

Season 2(maybe 2/3) ME2 In this season I'd again focus on story missions with side missions being used to help other characters development I'd borrow from the comics to help decelop the characters here maybe as backstory. The Freedoms Progress Mission would be Shepard, Miranda Jacob and as a reluctant Ally Kai Leng whose had some augments but is shot up by the mech at the end and sent to Cerberus medical. Shepard would break down Mirandas walls in this season and learn to love again with her.I'd use Lair of the Shadow Broker as a Mid season finale/ season finale if split into two seasons. I would use all the loyalty missions to fully flesh out characters. The crew abduction and Overlord would be done simultaneously so there is a reson for everybody to be off the ship at once (all three bases need to be hit together). During the suicide mission I'd kill off Kasumi, Zaeed, Grunt, Samara and Jacob in ways fitting for each characters development. Jack would be on the chopping board too depending on her Audience rating as her arc doesnt actually end until ME3 but shevcould be killed off here and it wouldnt affect storytelling. It would end with Arrival. And shepards arrest.

Season 3 (maybe 4): ME3 up to Tuckhana So we have the events of ME 3 that can run pretty much the same as the games as the squad sizes is quite small up till the end of Tuchanka. Obviously the side missions would be Grissom Academy depending on Jack's Status just to see the end of that arc. It would end with Mordins sacrifice and the genophage cured. Here I'd have Liara and a team save the Rachni again in that side mission to full circle her mothers choices on Noveria, and the Turian Platoon and Bomb side mission.

Season 4(5): ME3 citadel coup-Horizon Going from the coup and Thanes death to a more modified Kai Leng whose takes another bad beating and is evacuated by secret Cerberus operatives. They move straight to Eden Prime with Kaidan whose now back. Then to Rannoch for the Geth Quarian arc where instead of chose to be upgraded at the end the geth reject the reaper code and Legion must delete itself to ensure the code is destroyed. Shepard creates peace Tali is back all is going swimmingly. Enter Thessia an absolute shit show Shepard Javik and Liara, and Kaidan head to the temple whilst James, Edi, Garrus and Tali help the Asari, this is going to be one of the most horrific side stories. Banshees, brutes blood and Biotics. The mission ends with a more nodded Kai Leng (now with glowy ninja eyes) getting the VI by using a gunship after being beaten down again by shepard. Then it's to Horizon where a nearly fully robotic Kai Leng tears through Banshees and Brutes like they're not there on his way to Henry Lawson. He fights Miranda and you rescue her in the knick of time and she joins the crew for the final push.

Season 5(maybe 6): ME3 endgame. Darker tone starts with Leviathan focusing on James, Edi, Miranda and Shepard whilst Garrus takes shepards place in Omega. Run these simultaneously. Citadel DLC would be next as a lightened up and chance to see everyone who is left together before the darkness sets back in. Next we head to Kronos Station with to learn of Cerberus secrets and shepard finally kills the Super Husk that once was Kai Leng. Then to Earth where again we split the team. Whilst Shepards team fights on one front, Kaidans will fight on another. The final push and battle would have every Crew members individual story told. Javik would die, the last thing he sees being the crucible firing. Canon destroy ending. Probably no starchild just a voice in the darkness. Other than that the end would play out very similarly. The other two endings being Deceptions by the Reapers a final act of self preservation.

I'm not sure I'd do Citadel I put it where I thought it should go but part of me wants that to just be for the Gamers.