Super Street Fighter II Turbo was ported over to the Amiga from the PC. The graphics are the same as the PC and 3DO versions of the game, so the sprites are full colour, full size, and the backgrounds are lush and colourful with parallax floors. Unfortunately, because whoever ported it over to the Amiga hadn't a {bleep}ing clue how to code for the Amiga, it plays like {bleep}, even if you reduce the detail. It also has no speech in the game, just a generic thud sound for when you get hit. Looks beautiful if you pause it, makes you angry at the world to play it though. Also, only the CD32 version has music, which, being CD quality is prety good, but this version is considered the rarest CD32 game ever made.
On the other hand, you have Super Street Fighter II : The New Challengers for the A1200/A4000. It is the exact opposite of the Turbo version. The graphics are utter {bleep}, but it has all the speech samples, even though the music is slightly twiddly.
This version was ported over from the SNES of all things, although it would have made a lot more sense to port the Mega Drive version, using the same CPU and all it should have made the code easier to convert. Luckily for us though, the gameplay is perfect. It has options for a 2-button joystick/pad and a CD32 pad option, which gives you all three punch and kick levels, and the pause button.
The title screen and selection menu screens look nice, but the sprites are tiny, the colours are off, and the backgrounds look as though they were scanned from screenshots in a magazine at low resolution and dithered and shrunk or something. Fortunately you can switch the game from PAL to NTSC to make the graphics fill the screen a little bit more (as you can also do in the Turbo version). There is also no parallax or animation in the backgrounds.
The ECS version is just a cut down version of the AGA version. The gameplay is exactly the same, although it only has 1-button and 2-button options, and keyboard, but no CD32 pad option (even though the ECS version of Fightin' Spirit had this option, so it is possible to include support for it). Also, you will have to choose between sound effects and music. You can play the game with all the speech samples, but no music, or you can play it with the same music from the AGA version, but all the speech is gone, although it will still make hitting sounds. The graphics have a lot less colours than the AGA version, so it looks even worse.
Both versions of SSFII have WHDLoad installers. The AGA version's standard installer requires you to have a boot disk in the drive or it won't boot up. There was a CD32 version made and reviewed, but never released.
Then we have the old Street Fighter II : The World Warrior. Large sprites (although not quite arcade size), and nice backgrounds, although the colour palette used is a bit weird, and perhaps some dithering would have made the whole game look less flat. There was no parallax backgrounds or floors, although there is minimal animation in the background. The gameplay was slightly laggy, not as fast as it should and could have been, but it still played okay compared to what other Amiga fighting games were out at the time. There was a 2-button and keyboard option, although the controls are still a bit odd. Perhaps if the game went through a few more weeks of game testing and touching up, it would have been better than the console versions.
Overall, if you want to show your friends that the Amiga can play a nice looking version of Street Fighter, show them SSFII Turbo. If you want to play the game yourself and have some fun, play the AGA version of SSFII. And if you just want to play the best arcade style fighting game on the Amiga, get Fightin' Spirit. You can usually find brand new copies of the game still available in some Amiga shops and on eBay, since it came out towards the end and by that time there weren't enough people to buy it. It is a quality game, very similar to SNK's arcade fighters (Fatal Fury/King of Fighters).