Soulcalibur III

The only fighting game I ever loved. I'd spend unhealthy amounts of time in this game, unlocked every character, did everyone's campaign, loved everything about it. My favorite characters were probably Cervantes, Ivy and her sword, Yoshimitsu, Raphael (mostly for his name, but I loved playing as him as well), but above all were Setsuka and Taki, I think. Playing as Taki was satisfying as hell, and Setsuka's stage and theme, and the umbrella sword, have stuck with me forever. I was also pretty good at Siegfried and Sophitia.
The backstories, stage design, movesets, I loved it all back then, and if I were to revisit the game today, I think I'd feel about the same. I also loved the alternate paths you could take in the storyline, leading you to fights against bonus opponents, visiting other stages, fighting a huge stone statue called Colossus, or the secret final boss, Night Terror. I remember 8 year-old me trying again and again to reach him after doing it once, before erasing my memory card on accident. The quicktime events in the endings were cool as well, the soundtrack was the shit, I love everything about this game.

I can see how the overall reduction of the multiplayer suite might have soured some, and some of the new characters ain't great, but the single player offerings are off the wall in this one. Standard arcade and survival modes, tournaments and leagues to score cash with, a CYOA arcade mode with some very well-hidden secrets and a surprising wealth of story beats, a great first stab at create-a-character and a full-fledged RTS story mode with its own dense mythology. I could not stop playing this game because there was always something new to do, high praise for a fighting game. 2's Weapon Master still rules supreme.