Sonic 2
One of the best platformers ever made. It takes what made Sonic 1 good and adds to it to make an even better game. The inclusion of spin dash helps keep the game moving fast even when momentum is lost and the level design is all around better and far more memorable. Places from the Chemical Plant to Casino Night and the infamous 3 act Metropolis are all structurally unique and boosted by amazing music. The inclusion of Super Sonic for the first time also adds a replay value to the game in an effort to get every Chaos Emerald and replay the game even faster. Overall, Sonic 2 manages to completely top its predecessor, making it one of the best games of all time.
Sonic 3 &Knuckles
One again evolving off of the original Sonic experience, Sonic 3 & Knuckles to be a fun game. Although technically split into 2 games, the experience is bettered by playing them back to back. The level design at times, is possibly the franchise's best. The dynamic movement from stage to stage adds a level of immersion past Sonic games.The boss design is particularly fascinating, and the music is on par with the original games. All in all, Sonic 3 & Knuckles is a great closure to the original Sonic trilogy.
Sonic Adventure 2
Sonic Adventure 2 is an experience that defines Sonic for many. A sequel to Sonic Adventure, Adventure 2 takes its predecessor's gameplay to a whole new level. Adding levels designed specifically for Speed, Exploration, and Shooting characters, the game creates one of the most engaging narratives in Sonic despite its cliches and strangeness. Being the introduction to franchise favorite characters such as Rogue and Shadow, the game boasts many of the most memorable boss encounters and set pieces in the franchise history: from the G.U.N. truck chase to the final showdown between Sonic and Shadow. Overall, this game is a fantastic adaption of Sonic unlike any other.
Sonic 1
The one and only original game, Sonic 1 is. Introducing the original Sonic physics, you play through various platform heavy stages, trying your best to maintain momentum and speed to get as fast as possible to the goal. Although some stages are designed in ways that deliberately break one's momentum, the overall layout of the stages is a fun challenge, and the amazing soundtrack defines each one in its own way. The first conflict against Dr. Robotnik is easily one of the best in the series.
Sonic Rush
Rush is a fast, modern, 2D Sonic designed for the DS. Creating elements that would later be used in Unleashed, Rush pushes the Sonic experience by emphasizing speed through boosts in fun obstacle course stages. The bosses are quite a challenge, yet they often prove to be some of the most interesting in the franchise. The occasional enemy combat rooms show up but the pacing is never entirely put off. The addition of Blaze the Cat offers an extension of gameplay by giving you twice as much to do. Aside from the difficulty spikes at times, Rush is a fantastic experience of modern sonic adapted to the classic Sonic design.
Sonic Generations
Sonic Generations is a reunion of classic and modern Sonic in the perfect way. Generations adapts the physics of the original Genesis Sonic and takes the physics of the modern Unleashed Sonic to create two separate but fun level styles to play through the game. Although there is questionable level choice(many levels follow the "Green Hill" way of being the first area or green area in their game), the game delivers on reinventing these familiar Sonic stages for both gameplay styles, adding in an amazing soundtrack as well. However, the lack of originality does hurt the game as one would like to see more from this combination of gameplay than simply retread the same past stages.
Sonic Colors
A focused game taking the best elements of the Unleashed game and evolving from that. Multiple zones available that also bring the gameplay element of Wisps, creatures that act as power-ups for Sonic. The Wisps give an element of exploration unique to Modern Sonic games and add replay value in one's efforts to collect anything missed the first time around if a Wisp was unusable at a time. Lack of strong bosses and over saturation in missions and acts push the game's quality down.
Sonic Heroes
A callback, more so than the adventure games, to the original Sonic. The addition of 3 characters being controlled by you in one stage gives a diverse movement across levels and paths. However camera issues and confusing areas hold back this game's full potential. Still, this is a severely underrated Sonic game.
Sonic Unleashed
Unleashed has great day stages with wonderful music and unique speed emphasized design. This is marred however by slow, and combat focused Werehog stages which break up the pacing for too often regardless of their quality which can vary.
Sonic CD
Sonic CD is a fast paced evolution of the classic Sonic formula. Adding in time travel, the game allows you to experience multiple pathways based on choices made while exploring levels. The experience however, can be brought down by unfair bosses and frustrating level design.
Sonic Adventure
The first entrance into the world of 3D is a strange one in Sonic Adventure. Not quite sure exactly what it is, Sonic Adventure takes the classic Sonic gameplay design and tweaks it for its added dimension. The addition of a homing attack is fun, but poor control and camera issues keep the game from being great. The poor game design outside of stages as well mark down the experience.
