Super Mario Galaxy (Wii, 2007)

If there is a feeling of joy and flight that comes with every Mario game, then Super Mario Galaxy (2007) is the one that achieves it the most.  Super Mario Bros. 3 and Super Mario World got Mario off the ground, Super Mario 64 brought him into the third dimension, but this game rockets him past the stars and into the deepest reaches of space, both figuratively and literally.  In this game, Bowser has once again kidnapped Peach and brought her into distant space, and Mario finds himself aboard the comet observatory, a space station whose power stars have also been stolen by the King of the Koopas.  Mario is aided in his quest by Rosalina, the master of the observatory and mother to the lumas, a race of tiny star children, who are destined to become some kind of celestial body when they grow up.
To regain power to the comet observatory, Mario must travel to distant galaxies to retrieve the stars.  These galaxies make up the levels of the game, similar to Super Mario 64's painting worlds.  The more stars you collect, the more galaxies the comet observatory can send you to.  Other galaxies become accessible when you feed star bits (collectible throughout the game like coins) to hungry lumas.  The comet observatory itself is like a big level with places to explore and some secrets to find, similar to Peach's castle.
It should be noted here that this is a Wii game, and therefore involves motion controls.  Most games made on the Wii before and after this game felt the need to shoehorn in its motion controls, most of which did not function properly.  This led to many awful titles on the system, and the coining of the term "shovelware".  Super Mario Galaxy is careful not to make its motion controls seem out of place or dysfunctional.  Shaking the remote will make Mario do a spinning attack, which can also be used in mid-air to gain a little more height.  Combined with the ground-pound, it can be a powerful homing attack.  Pointing at the screen will move a cursor which can be used to pick up and fire star bits (used to stun foes).  In certain levels, Mario will balance atop a giant ball, and you tilt the remote to steer him.
Platforming has been completely re-vamped for this game.  Each galaxy is made up of a number of planets and planetoids, rarely being flat.  In the first galaxy, Mario stars on a small planet with seemingly very little on it.  He jumps off the edge, orbiting around to the other side, revealing that there is more of this planet to explore.  Gravity twists and bends in all directions depending on the size and shape of the planets.  One planet will be so large that it seems to be flat, and another will snake around offering all kinds of gravity-bending possibilities.  Platforming puzzles and boss fights often revolve around these shifts in gravitational force.
This is one of the most beautiful games I have ever seen.  The Wii is not known as a graphics powerhouse, but Super Mario Galaxy takes its 256 bits to the limit, crafting a game that is colorful, detailed, and marvelously textured.  Every object and character feels like the have a weight to them, and are drawn with such detail as to look real.  The size and majesty of each galaxy is something to behold.  One of my favorite lines from The Hitchhiker's Guide to the Galaxy states that "Infinity is not very impressive, just look at the sky and there it is.  What is more impressive is something that seems infinitely massive."  That's the feeling of this game.  Infinitely massive and grand.