One Step Forward, Two Steps Back

There are many opinions on what the "best Sonic" is. Though the characters of the Sonic series mainly stay the same, some have shown development. Including Sonic...at one time, anyway. 

ONE STEP FORWARD

From an Impatient Hero 

The classic games lacked dialogue but still showed personality. Sonic was very impatient, often tapping his foot or even jumping off screen. His appearance was also edgy with attitude put into his various poses. Even making him a teenager was a sharp contrast to Mario's goofy design.

He was a hero, firstly taking on Dr. Robotnik all by himself. Sonic was also a role model for Tails and didn't hold a grudge against Knuckles for all he did in S3.

In the Adventure series Sonic was more laid back, usually drawn into the conflict. Still thick with attitude, he didn't stick around often.

To a "Friendly" Thrill Seeker

By Heroes he was rushing to stop Eggman, though, eager for the thrill. This became a common scenario. The value of relying on others became more obvious for him.

Sonic made friends easily and was willing to help those who needed him. He also looked forward to taking on "new competition," and proving he was the fastest in any field.

To a Defender of Worlds 

Sonic never cared about the risk to him, though he would get angry at a foe, especially if his friends were in danger or harmed.

In games like Unleashed and The Black Knight, Sonic still had attitude and impatience but was also more serious when faced with the weight of certain situations.

"Development" 

While his 90s-based personality was largely the same, Sonic was changing. Sonic started as a hero, of course. An impatient one who gained an appreciation for friends yet became a leader and helped inspire others. Carefree, the hedgehog found fun in his adventures, but began to recognize the difference between an easy fight and a true threat. Sonic was not afraid to fight until the end to save his world (or someone else's).

So though Sonic seems static from a far, his fights with Eggman and other foes left him more mature over the years. It's possible that Sega could have taken this further. But we'll never know because...

TWO STEPS BACK

A Joker

Sonic Colors over-saturated Sonic's humorous nature, and since the game was well received (for reasons I'll never understand), this affected Sonic's future. While always having a bit of the 90s with him in the past, he seemed to adopt 2010 instead ("EPIC").

Ultimately their were so many jokes that they weren't very funny, and the plots became lighter and impossible to take seriously. With the tension gone, there was little reason to play the games or see them as unique.

A Lonely Extrovert

Sonic largely ditched the "leader" idea, not even relying on long-time bud Tails much. He left the fox to do technical work alone instead.

In Sonic Rush Sonic convinced Blaze that relying on others was not only okay--but necessary sometimes. Yet in every game since Sonic Colors he only allowed his friends supporting roles (with the exception of racing spin-offs).

He trusts "classic" Sonic, but that was himself!!! And in Forces he begins to trust the Avatar, but why would "buddy" get priority over longtime friends like Tails or even close rivals like Shadow?  In 06 Shadow admitted he couldn't take on Solaris with out help from Sonic--would Sonic admit the same about Shadow? Not the 2010s, it seems.

When Sharah was seemingly killed in Sonic and the Secret Rings, Sonic turned dark; he was fueled by the emotions sorrow, anger, and hatred of the World Rings. Yet when his closest friends are all consumed by the "Time Eater," calling out to him...all he says is "not cool."

It's hard to even know if Sonic cares about anyone anymore. In the rare occasions when they are around, Sonic hardly interacts with them.

A Ego Maniac

Sonic is still heroic, but he gained an ego over his many wins. While in Sonic Adventure Sonic had simply left instead of taking credit, and in Sonic and the Black Knight the hedgehog actually passed a test over chivalry, from Colors-on Sonic has excessively bragged that he will always beat Eggman.

He also dismissed the Time Eater as a threat, sighting past wins and claiming it was "no different."

Sonic's always tried to be the best, but he didn't insist upon it like Jet. At least he didn't before. Somehow Sonic became overconfident.

Though TSR arguably portrayed Sonic better (since he was working with his team again), he kept blabbing about racing (winning).

And Stoic

Though Sonic Forces was an attempt at a deeper plot, the blue blur wasn't back on track. The character had been "tortured" and declared "dead," but his personality revealed him as completely nonchalant and even a bit crude.

"Un-Development"

Overall Sonic has been shallower than ever before. "Colors Sonic" (2010) is virtually indistinguishable from "Forces Sonic" (2017). And his unconcerned behavior is unnatural, at this point.

Sega didn't learn from their mistakes, they listened to people complain about them. Instead of thinking about how they could have been improved, Sega simply ignored any game rated poorly without understanding "why."

They choose what was a well-received gameplay style, and cut off most of the characters. Meanwhile they watered down the plot since "simpler" competitors like Mario were well received. Colors wasn't a reboot of any kind, but after it's success Sega acted like it. 

Sonic's become static as a consequence. Hopefully Sega will listen to the complaints about Sonic in Forces and guide the character back--because otherwise he'll never change. 

There's no doubt that each of the cartoons helped bring his personality to focus, no matter if "Thrill-Seeker" or "Ego Maniac." The comics deserve some credit as well. While the new Movie and IDW have shown some potential in trying to reform the character, Sega itself fears risk.