Sonic is a blue low-tempered hedgehog who likes to show off his speed and be the hero of almost everything. This is why he doesn't sit down and do nothing while Robotnik or Eggman try to conquer the world.
Sonic Rush happened in 2005.
Sonic Advance happened in 2001.
Sonic Blast happened in 1997.
Sonic Jam happened in 1997.
Sonic Unleashed happened in 360.
Sonic Heroes happened in 2003.
Sonic Colors happened in 2010.
Sonic R happened in 1997.
Sonic Battle happened in 2003.
Sonic Eraser happened in 1991.
Sonic Riders happened in 2006.
Sonic Labyrinth happened in 1995.