Sonic Adventure 2 and Sonic 2 my goats. I also loved the Sonic Rush games, Sonic Heroes, Secret Rings to some degree and the Sonic Advance gsames too.
Gonna get Frontiers sooner or later, never got to try the Black Knight one, hated Colours when I tried it but regretting it now after seeing one of the levels and how INSANELY BEAUTIFUL it is at least, I also did enjoy Unleashed especially the music and Sonic levels, not the Werehog stuff much though especially with how forced and abundant it was. Not tried Forces but not bothered yet, nor not tried Mania yet either.
The Sonic Adventure games era was amazing though. Also the Mega Drive/Genesis era. I really enjoyed the 2nd Sonic movie too, the 1st one was surprisingly good too. 2nd movie gets too much hate imo, except for that ridiculously, overly long, cringy wedding scene/storyline but Idris Elba Knuckles was fantastic and they did some AMAZING fanservice/tributes too for the classic games! (DEATH EGG, BABY!)
Have you tried the Freedom Planet games too by any chance? Supposed to be pretty good and similar. Sonic Mania is the best of what you can get now apparently but Frontiers is pretty decent apparently. I didn't try Lost World either to think of it, keep forgetting about it.
I also loved the Sonic racing games, not Sonic R as much but the kart racer ones. Not tried Team Sonic Racing the new one but the previous 2 were FANTASTIC imo!
Sonic Adventure 2 was really something else though, I still really love/cherish that game despite some fucking awful levels later on in it too lol. It was truly experimental, daring, unapologetic, chaotic (pun intended), gave us Shadow ofc, EPIC music and levels and so on.