Poor year for me. I'd say even from the list and games mentioned, the fact that DMC2 is mentioned which is generally considered the worst DMC game.
For me, if it was't for PAL getting games late, I would say I wouldn't have play much this year. Infact as it was well into my Uni years, there wasn't as much anyway. I got SC2 this year (which arcade release in 2002) and still playing left overs from 2002 or FF games again.
If I had to vote for anything here, it would be Eye Toy. Many might not think it significant but it's influence was actually held for years and it's idea used in the next gen like it was a rash.
Hmm, pie.