I still prefer Super Mario 64. I'm not just being some old fart saying that old = better, but I just feel that Super Mario 64 was more immersive. Super Mario Galaxy is too linear for my liking - you move from planet a --> b --> c --> ... --> last planet, and there is often no or little way to go backwards through a level. I much prefered the immersive areas of Super Mario 64 where youc ould go nearly anywhere in the level. Yes in Super Mario 64 there were some areas you could only get to when you were after certain stars but they were often only small differences, and they actually added to the game play as each level was different.
In Super Mario 64, you were also able to get stars from later on in the level - surely everyone who's played the game remembers the joy when theyc ame across a star that was not the one in the level description.
That's not to say that galaxy was a bad game, it's problem was that Super Mario 64 was an outstanding game, which Galaxy was unable to live up to.
There is light at the end of the tunnel ... or is it just an oncoming train.