Board Thread:Questions and Answers/@comment-9831152-20130923082601/@comment-1392727-20130923115145

Silver and Blaze being 'best friends' is exclusive to the story of Sonic 06 [you might count Sonic Colors (DS) but they simply met]. In the continuity of most games, her best friends are Cream and Sonic.

Cream - Sonic Rush, Sonic Generations Sonic, Sonic Rush (ending only), Sonic Rush Adventure, Sonic and the Black Knight, Sonic Generations (biography only mentions Sonic as her friend)