I do not think they have missed best levels of each games, on the contray, I think they have picked the levels that best represent each particular game [spoiler:pufghkfn]que joke about how a half broken disaster zone in Crisis City best represent Silver 06, I actually think you are very wrong about them missing the best stages because outside of Ice Cap, I agree with the choices as they are known as the best levels of each game.[/spoiler:pufghkfn] But that is the problem, if you add them altogether, they do not make a very good selection. I was already worrying when they said they chose them based on everyone's choices.
My major gripe is the level order [spoiler:pufghkfn]Classic > Adventure > Modern?[/spoiler:pufghkfn] I am perfectly fine with each era get a specific amount of levels, however [spoiler:pufghkfn]the fact that Sky Sancutuary and Death Egg (As well as Metal Sonic) are so early in the game is plain wrong[/spoiler:pufghkfn] it does not help the game goes from amazing memories to sourer memories thanks to the order.
Infact, if I had to pick the levels [spoiler:pufghkfn]Green Hill Zone, Chemical Plant Zone, Ice Cap, Red Mountain, Pyramid Cave, Hang Castle, Crisis City, Eggmanland and Terminal Velocity (Extend it into a full level)[/spoiler:pufghkfn] of course not all of those are best representations of their respective titles, but a healthy mix of levels. At the same time [spoiler:pufghkfn]I would probably have not made the order classic > adventure > modern but a mixed order.[/spoiler:pufghkfn]
[spoiler:pufghkfn]Still, no Sonic CD or Sonic 3 is borderline stupid, both games outsold Silver and have a higher critical reception, they have a better reason to be in this game than Silver.[/spoiler:pufghkfn]