Assassin's Creed (2007)
Time Period: 1191
Location: Holy Land
Your Assassin: Altaïr Ibn-La'Ahad
Modern Day: Desmond Miles
My Thoughts: I first played this in 2026 on my Steam Deck and was really surprised by how well it holds up. The graphics on the small screen were charming and it was really cute to see where the game play and ideas of the series all started. It's old as hell but I do recommend that you start here to get the set up of the Animus and the conflict between the Templars and Assassins.
Pros: Altaïr's name is fun to say, I cannot imagine a new game in 2026 presenting itself as "you are killing Templars in ancient Jerusalem" and getting away with it, the plot reasoning for this grown man having to start over as an Assassin made sense, good little character arc for our man Altaïr, Kristen Bell is in it and this was made before I was oversaturated on her
Cons: I would have expected to learn literally anything about the time period or region and I didn't really, the chase scene at the docks almost made me rage quit and watch a playthrough instead(but I'm glad I worked through it), can get very button mash-y if you don't bother to learn to block and counter (this is a personal flaw of mine that I am working on).

Assassin's Creed II (2009)
Time Period: 1459 - 1497
Location: Renaissance Italy!!
Your Assassin: Ezio Auditore da Firenze
Modern Day: Desmond Miles
My Thoughts: This is controversial, but I think you can skip this one. I thought Ezio was a fuckboi(TM), I did not care about his vengeance, and he only had the slightest bit of character growth at the end. The parkour in this game is highly regarded but I only found it really fun and satisfying 1/3 of the time. The other 2/3rds I thought it was some of the most frustrating gameplay possible.
Pros: One of the most satisfying endings of any game I have ever played, you also get to curbstomp the Pope, the courtesan outfits were so cute, game was straight up unhinged at points.
Cons: Button-mashy, parkour irritating, the plot was boring and the assassinations felt inconsequential.
My summary for you if you decide to skip this game: Leonardo da Vinci is inexplicably Ezio's bestie and you test his flying machine, they worked in a it's-a me, Mario, THIS GAME IS WHERE VARRIC'S (Dragon Age) CROSSBOW BEING NAMED BIANCA IS FROM, if you're going to skip the game you should at least watch this from the ending because it admittedly did rule.