What was your first Assassin's Creed game and what did you love about it?

Recently got back into this series after not playing for years and am catching up on the last few games I missed out on. Which game was your first of the series and what did you love about it that kept you coming back to the series? For me, Assassin's Creed 2- it was the phenomenal story and the unique gameplay, particularly the stealth aspects. Really enjoying this nostalgic experience of returning to these games and it would be cool to know what got others into this series.