Hmmm... Perfect video game. Have played some very near perfect ones in my time.
Off the top of my head.
The story and dialogue choices of a Bioware game
The addictiveness, level system amd general humour from Gearbox
The cutscenes and art direction from Yuji Shimomura (DMC 3)
Character Creation tools from Saints Row
Music from Yuzu Koshiro (Streets of Rage)
Insight and creative direction from David Cage (Heavy Rain)
Completely personal what people view as a perfect game though but this would satisfy me from a basic components and hopefully all working together to produce something amazing:-)