If you mean the official powered-up triple jump then you need all 120 stars.
If you mean the Action Replay / GameShark etc. hacks then these are totally independent of how many stars you have.
There is currently no Super Mario Galaxy 3. If you mean Super Mario Galaxy 2 there are 242 stars.
There's 150 power stars in Super Mario 64 DS.
There are 4, Super Mario Bros. 1, Super Mario Bros. 2 and Super Mario Bros. 3, there is also Super Mario Bros. The Lost Levels which is the original Super Mario Bros. 2 in Japan. They have also made a remake of Super Mario All-Stars for Nintendo Wii.
Rosalina is not in Super Mario Kart. She is in Mario Kart Wii.
6 stars
Theres No Super Mario 64 For Wii.
122 power stars and 120 green stars.
any number of stars with luigi or all 150 stars
5
120.
Super Mario Bros. is a popular game which was released to play with the Nintendo gaming system. The original Super Mario Bros was released in 1985. Since then many more have been released including Super Mario Bros. Special, Super Mario Bros 2, Super Mario Land, Super Mario World, Super Mario Cart and Super Mario All Stars. There are over 200 games available which fall under the Super Mario Bros. Games.
Although there are 150 stars in total, you only need 80 stars (and Mario) to complete the game as this is the number of stars you need to get into the final Bowser level.