It is widely considered that Mario 64 is one of, if not the best, 3D platformers of all time and certainly the best from Mario. I have to say until recently I agreed with this entirely because, quite frankly, the game is absolutely fantastic, even today. What changed my mind then? Surely it must have been something of "cough cough" Galactic proportions?
Yeah that's it, Mario Galaxy and then Mario Galaxy 2 changed my mind. Mario Galaxy took the franchise where no Mario game had been before and made one of the greatest games of all time in the process. The gameplay was fun, the design innovative and the whole experience was wonderful from start to finish. The sequel only served to improve upon the game by adding several ideas that Miyamoto says the development team did not have time to include. These ideas took a genre and franchise defining experience and did the impossible: they made it even better.
Despite the Wii being the best selling console of this generation there are many, many naysayers. It's amazing games like Super Mario Galaxy and Super Mario Galaxy 2 that give us fans of the Wii plenty of ammunition to counter them. I don't think that these are the best of all time, and I haven't played enough 3D platformers to say they are the best there but they are certainly the best 3D Mario games and are the two best games that the Wii has to offer.