What is the most popular couple in Sonic

It truly depends on who you ask and where and when. A couple couples that have fanatics about them include:

Sonic x Amy
Sonic x Sally
Sonic x Blaze
Sonic x Mina
Sonic x Cream (strangely enough)
Tails x Cream
Tails x Amy (for some reason)
Tails x Cosmo
Tails x Mina
Knuckles x Rouge (including myself)
Knuckles x Tikal (a bit necromatic in my opinion)
Knuckles x Shade (even though she only appears in one game)
Knuckles x Julie-Su
Knuckles x Sonia
Shadow x Rouge (my best friend is a supporter of this couple)
Shadow x Maria (despite their obvious brother-sister relationship)
Shadow x Amy (mostly because of his likeness of Sonic)
Shadow x Tikal (don't ask why)
Silver x Blaze
Silver x Amy

Those are the BIG 20.

Of course, there are those perverts who think it's funny to say some of the characters are gay.

Sonic x Tails, Sonic x Shadow, and Sonic x Knuckles, etc. I do not approve of any of those and you probably shouldn't read too much into this...