Products of humanity are imperfect, just as humanity itself. So how can games be perfect?
Anyway...
Halo Combat Evolved: This system seller redefined the first person shooter genre with its level design, timeless controls, vehicle use, physics, and much much more. It truly was combat evolved. But that wasn't all Halo had to offer us gamers, it gave us an iconic character with the Master Chief, an unforgettable story in an amazing universe, and some of the greatest video game music I ever had the pleasure of listening to.
Super Mario Bros. 3: Took an amazing formula, and made it 100 times better with its unique environments, improved level design, gameplay mechanics, and some of gaming's most memorable soundtracks.
Resident Evil REmake: Known as the definition of a remake, Resident Evil took a classic, and turned it into a masterpiece.