For someone planning on doing a comic, what games do you think would be worth watching to study Modern Sonic's character ? Also for classic Sonic we can't really watch anything, we see it as we play but I'm interested in knowing how you see him exactly.
The games that portray Modern Sonic well in terms of adhering to his personality, mannerisms and the like and which are worth paying attention to for the sake of fanwork are;
The two Sonic Adventure games.
DEFINITELY the Storybook games. These are practically flawless in their portrayals of Sonic in my view and are a fantastic standard by which to abide by if you’re doing fan work and wish to stay true to character. A hint though; What makes the Storybook games so good is not just the way the character is portrayed in cutscenes. In-level dialogue is also an important facet of these portrayals, so I recommend watching playthroughs.
As for my own personal interpretation of Classic Sonic’s character in the Classic games?
Well, I get the impression that he’s a tad more serious than his future self, has a decent degree of resourcefulness and is more ‘hands-on’ in regards to taking-on Eggman. This was evidenced in Generations when there was a distinct difference in the way Classic and Modern reacted to Eggman’s voice in that dark mirror room - Modern looked exasperated and stood where he was whilst Classic wasted no time in his pursuit of Eggman, suggesting that he takes him more seriously than Modern does.
Classic also seems to be more shirty regarding his impatience.