My Favorite character is Tails because he's so adorable, I remember making a lot of sonic oc's in my life and one of them was a one tailed fox named skye the fox (who was clearly inspired through lack of a better word off tails) instead of using his tail to fly (Because it would be impossible with just the one.) he Used Gagets he relied on them a lot more then tails ever does. (I Occasionally play as skye in sonic robo blast 2)
I think my favorite would be Dr. Robotnik just from how he presents himself all the time; mad scientist held back only by his childish attitude. Honestly any time he's on screen I just wanna see everything from his perspective!
Though Blaze has been showing up on my mind a lot lately. I have a little bit of nostalgia for her from playing Sonic Rush like 5 or 6 years ago, but that's about it. Always serious yet never really "there" as the big leader I guess, always lost. (lets hope these thoughts arent for the worst)