If you buy the game on Steam, you can still download fan-made .rar files that replace the official ROMs with hacked versions (e.g., Super Street Fighter II Turbo: Grand Master Challenge ). This gives you the legal base + the pirated mod.
: Four of the most popular titles— SFII: Hyper Fighting, Super SFII: Turbo, Alpha 3, and 3rd Strike —feature online lobbies and ranked play. Street-Fighter-30th-Anniversary-Collection.rar
The official collection includes: