I'm curious what you guys have to say about this. Are there any games you consider perfect? Can a game even be perfect?
My example of a perfect game is always Portal 1. Portal 2 has more going on, but in 1 there just isn't anything to shave off. From start to end, there is nothing I'd change about the game. It's short, infinitely replayable, great pacing. I like Portal 2 a lot in concept, in concept it should be a perfect sequel, but it just doesn't keep the extreme tightness of the original game.
Metal Slug has the best pixel art, god-like soundtrack and that easy-to-learn-but-hard-to-master game play, with no contact damage! It's perfect.
Karian Cross crosses Puyo Puyo and Crazy Cross and births the perfect casual versus puzzle game. It's also probably the first and to this day one of the only versus puzzle games that has character specific musics in the two player battle mode. It's perfect.
Very happy to see that F-Zero GX was already mentioned; it is the best game ever, but a bit too hardcore to be perfect!