>>713263757 (OP)Sonic 3 & Knuckles is the best game.
Sonic 2 and Sonic CD are runner ups albeit with heavy caveats. If youre just trying to speed through them to the end, they're actually just kind of meh. They're better as platforms where you try to focus on ring collecting (and then in CD's case, time traveling for the best ending)
The original Sonic the Hedgehog is more of a blueprint for a game than a great game itself, but it is a decent challenge. I'd reccoemnd playing it after the others.
The racing spinoffs are hit and miss. IlUnless you have a friend to play them with, their value significantly declines. That being said the first Riders game is peak irl 2-person competitive gaming. For everything else, it's more or less a poor man's mario kart, but that's not to say they're bad.
Just like the original Sonic 1, the original Sonic Adventure is a better blueprint for a 3D Sonic game than a great game in its own right. It's oozing with turn-of-the-century high-fantasy/windowsXP Bliss wallpaper soul, and it has a few good levels, but the game as a whole is really rough. Sonic Adventire 2 is a tighter experience with less jank, but at the cost of being significantly more streamlined. For most people, this will be a better playthrough than Adventure 1 even if I have a lot of respect for the first game.
Sonic Heroes has an interesting gameplay loop but gets boring fast. Only play this and Shadow the Hedgehog if you're interested in seeing Shadow's trilogy be completed after SA2.
Listen to me very carefully. Every single boost game is shit. These are games where it's basically glorified temple run but with decent visuals and Sonic. Fans will try to tell you Unleashed is worth it. It isn't. Neither is Colors. Neither is pretty much any other 3D game in the last decade and a half. Just don't. And yes this includes Frontiers which is the Sonic equivalent of Halo Infinite.
Oh, and Mania is pretty good as a nod to the classics, albeit a bit overrated.
t. I'm 34