I thought a lot was right conceptually with Secret Rings and Black Knight, they were just designed to be overly gimmicky and suffered greatly (stuff like having to unlock good controls should not exist). If a normal game was made in a similar style, I could honestly see myself getting pretty excited for them.
Black Knight gets way too much hate though. The game is not very good at all of course, but it was announced at the worst time with EVERYONE ready to finally accept Sonic Unleashed, even the werehog. Because it was announced too early and everyone freaked out, I feel Unleashed got a much worse reception than it would have without Black Knight.
There are literally billions of books that would probably work well with Sonic characters in some form, but personally I would really like to see Sonic and the Journey to the West. Sonic Bible Adventures would also be cool, if not just to see Sharky and Shadi freak out bad.
As for a new Superstars game... Doubt I could get excited for a new sport, and I do not want anyone outside of AM2 or MAYBE AM4 making a fighting game or something similar. I loved SUMO's racing and tennis, but they focus on stuff like Sonic Team properties far too much. Regardless of how cool they came out, three Samba De Amigo levels is just stupid. Do not get me started on Billy Hatcher.