FF6 - didnt play it untill its gba version but quickly fell in love with the game. It might have been my kid brain but i found the story to be amazing.
Castle wolfenstein enemy territory - this was an online fps from the early 2000s, i dont know what game ive sunk the most hours in, but this could be it. I loved this game so much that i just could never get into any online console fps.
Mass effect 2 - i loved the first game for its atmosphere and setting, then a few years later this masterpiece came out expanding the universe while overhauling the gameply in such a way it made my teenager self get all emotional. Then the third one came out next year or something and pissed me off with its ending but whatever.
Honorable mention
Fromsoft studioe’s games - i think i can safely say im now in a committed relationship with soul games, but they werent my first loves.