Do it now.

I'm gonna die by the time I finish

Main series of spin-offs included? Would I include games where Sonic’s name isn’t in the title, like “Shadow the Hedgehog?” What about games that feature sonic, but where his franchise isn’t the main focus, like the “Sonic and SEGA all star racing” games?

Wish me luck, I'm naming most of them but I don't know all by heart... Sonic The Hedgehog, Sonic The Hedgehog 2, Sonic CD, Sonic 3 And Knuckles, Sonic R, Sonic Adventure 1, Sonic Adventure 2, Sonic Hero's, Sonic 4 Episode 1, Sonic And The Black Knight, Sonic Unleashed, Sonic Riders, Sonic Colors, Sonic And All Stars Racing Transformed, Sonic Generations, Sonic Boom Rise Of Lyric, Sonic Lost World, Sonic Forces, Sonic Racing and Sonic Frontiers.

What about runners

And all the other Sonic games technically angry birds epic counts

ik.. I just wanted to try remembering most of them without research

Too easy, piece o' cake
Sonic The Hedgehog, Sonic 2, Sonic CD, Sonic 3, Sonic and Knuckles, Blue Spheres, Sonic R, Sonic 3D Blast, Sonic & Knuckles and Sonic 2, S&K+Sonic 3, Sonic Adventure, Sonic Adventure 2, Sonic 4 Episode 1 and 2, Sonic & All Stars Racing Transformed, Sonic Riders, Sonic Heroes, Team Sonic Racing, Sonic Riders Zero Gravity, Sonic Free Riders, Sonic Boom: Rise of Lyric, Sonic Frontiers, Sonic Generations, Sonic Colors
I know all the rest but I'm not gonna waste my time listing every Sonic game known to man

Doki Doki panic