Before going in with the list of main titles, it’s worth mentioning that the timeline of the canon Street Fighter titles is not very consistent. There are incoherences in some individual character stories between entries, restarting plots or characters being death and then alive, among other things. However, the following is the most accepted timeline in the series.
The game that started it all, Street Fighter doesn’t go deep in terms of presenting a story. You can only play as the iconic characters Ryu and Ken, looking to battle fighters in five different countries: Japan, England, the United States, China, and Thailand. The latter is where the final challengers are, Adon and Sagat.
In the first entry in the Alpha subseries, Warrior’s Dreams, Sagat is back and ready to take revenge on the man who defeated him. However, Alpha presents many more relevant characters than the original Street Fighter, including the iconic antagonist M. Bison.
Alpha 2 is mostly a reimagination of the previous one. Akuma and M. Bison continue to be the antagonist, fighting Ryu until death and establishing the criminal syndicate Shadaloo, respectively. These stories are more fleshed-out though, as Ryu’s encounter against Akuma involves a battle on Akuma’s island, which is destroyed by its owner by the power of a single fist. On his side, M. Bison keeps recruiting people for his organization, with the aim of obtaining Ryu’s body.
Some of the storylines presented in this subseries end in Street Fighter Alpha 3. M. Bison gains control of Ryu, who is in another state of mind with the evil force Satsui no Hado, while he also has the Psycho Drive, a machine capable of erasing complete towns.
Arguably the most popular game in the series, Street Fighter II: The World Warrior (and its multiple versions) revolve around the same setting: M. Bison is back, and he is hosting a world tournament that welcomes the best fighters from different parts of the globe.