Sonic 2 Pink Edition
Amy Rose and Cream the Rabbit are included in the Sonic 2 Pink Edition, a completely remixed version of Sonic 2. Amy has her piko piko hammer with her and can use it to great effect. Cream can fly and has a cheese attack.
Sonic Boy 2 Eggmans Trap
As a knight with a sword, Sonic fights the MEKA Dragon. Later on, you can even play as Sally and Tails!
Sonic 1 Sage 2010
Playing a time-attack game where you can select any act and level (including enemies) in an effort to beat the clock
Sonic Xs
Hurry! Amy Rose has been kidnapped by Doctor Eggman and only Sonic Xs can save her! To do so you must battle robots.
Mighty The Armadillo
This is one of the earliest Sonic rom hacks ever, with a new character and a modified Green Hill Zone.