I will quickly give my input for some games:
Sonic 1: Challenging, but too slow.
Sonic 2: Very good. I hate how you can't slide across the handle rails in Wing Fortress Zone, though. Barely making short jumps is really annoying. I would have really liked Death Egg Zone to be an actual zone.
Sonic 3 & Knuckles: Sonic Team's best. The levels are nice and large. Of course, Carnival Night Zone Act 2 isn't exactly...straightforward.
Sonic 3D Blast: Too slow, and too non-linear. But it was still fun.
Sonic Chaos: I've only played ports of the Game Gear version, and I must say that it suffers from one of the same problems as SRB2's 2D mode: small viewsize. The levels are way too short. With the Master System's larger resolution, I would imagine that it would be the more enjoyable version. Nice twist on Special Stages, though. I hate the glitch where if Tails gets 100 rings then gets hit, he dies.
Sonic Adventure DX: Has the occasional non-linearity, and the graphics are cool. The gameplay is OK.
Sonic Adventure 2: Battle: OK, seriously, don't design 3D levels the way you would design 2D levels. In 3D, we can avoid obstacles at full speed. And the whole death pit on the side was quite abused. Come on, the second level is over a death pit? At least the Emerald Hunt levels are MUCH better designed, being all huge and stuff. Tails's gameplay wasn't too bad, though. Crazy Gadget could have been completely awesome, but the whole "choose the middle switch in the room with three switches equals instant death" and to a much, MUCH larger extent, the last room, really pull this stage down from awesome to epic fail. The last room is almost as bad as a particular Sonic 3 gimmick.
Sonic Heroes: Quite fun. The whole play-as-three-characters is quite cool, and it makes gimmicks like frequent mini-bosses not that annoying. It IS overused, though.
Sonic Advance: The best of the Advance series. Egg Rocket Zone is too long, and has frequent cheap hits/deaths, though. I would have REALLY liked X-Zone to actually be a zone.
Sonic Advance 2: WAY too much emphasis on running. Hot Crater Zone Act 2 is REALLY abusive on running. The method of getting to the special stage was so annoying, and the seventh special stage is really hard.
Sonic Advance 3: Quite fun, but the tag action thing makes certain things too easy. The zone maps give actual challenges; that's really neat.
Sonic 1: Challenging, but too slow.
Sonic 2: Very good. I hate how you can't slide across the handle rails in Wing Fortress Zone, though. Barely making short jumps is really annoying. I would have really liked Death Egg Zone to be an actual zone.
Sonic 3 & Knuckles: Sonic Team's best. The levels are nice and large. Of course, Carnival Night Zone Act 2 isn't exactly...straightforward.
Sonic 3D Blast: Too slow, and too non-linear. But it was still fun.
Sonic Chaos: I've only played ports of the Game Gear version, and I must say that it suffers from one of the same problems as SRB2's 2D mode: small viewsize. The levels are way too short. With the Master System's larger resolution, I would imagine that it would be the more enjoyable version. Nice twist on Special Stages, though. I hate the glitch where if Tails gets 100 rings then gets hit, he dies.
Sonic Adventure DX: Has the occasional non-linearity, and the graphics are cool. The gameplay is OK.
Sonic Adventure 2: Battle: OK, seriously, don't design 3D levels the way you would design 2D levels. In 3D, we can avoid obstacles at full speed. And the whole death pit on the side was quite abused. Come on, the second level is over a death pit? At least the Emerald Hunt levels are MUCH better designed, being all huge and stuff. Tails's gameplay wasn't too bad, though. Crazy Gadget could have been completely awesome, but the whole "choose the middle switch in the room with three switches equals instant death" and to a much, MUCH larger extent, the last room, really pull this stage down from awesome to epic fail. The last room is almost as bad as a particular Sonic 3 gimmick.
Sonic Heroes: Quite fun. The whole play-as-three-characters is quite cool, and it makes gimmicks like frequent mini-bosses not that annoying. It IS overused, though.
Sonic Advance: The best of the Advance series. Egg Rocket Zone is too long, and has frequent cheap hits/deaths, though. I would have REALLY liked X-Zone to actually be a zone.
Sonic Advance 2: WAY too much emphasis on running. Hot Crater Zone Act 2 is REALLY abusive on running. The method of getting to the special stage was so annoying, and the seventh special stage is really hard.
Sonic Advance 3: Quite fun, but the tag action thing makes certain things too easy. The zone maps give actual challenges; that's really neat.