Sonic Colors is, by far, the most well-rounded of the bunch. Maybe a little bit sluggish, but mostly fast-paced. It's an absolute shame it's exclusive to Wii. But if I had to choose I'd still choose Sonic Adventure. I'd probably hate myself for owning a Switch or rant about the startup screen being different from the original. Despite the phenomenal feedback regarding FFVII Remake even Square Enix has still to do a lot of convincing (for example, why does it run on Unreal Engine 4, not their Luminous Engine? It bugs me a little). Sonic Team would have to think of the original SA1 as some kind of prototype while also taking into account a certain familiarity on the part of the fans. The worst-case scenario would be a Star Fox Zero-like scenario where the game isn't bad by today's standards, just a little underwhelming (poor Shigeru Miyamoto). Is now a good time to remake SA1? Yes, probably. Remakes of popular games are everywhere. Avoid simple design faux pas and don't let yourself get screwed by licensing issues, "get it right".