It seems like only the Japanase Arcade version and the Sega CD version are completely uncensored. The Japanese SNES versions are almost uncensored but still two enemies are censored here (Poison and Roxy).
The US Arcade Version is almost uncensored too. Only a short sequence during the intro has been censored here. This almost-uncensored-version has been released on the newer consoles as well (Capcom Classic Collection for PS2, PSP, Xbox and the PS3-Download version).
Heavily censored is the old console version. This concerns all international SNES-releases (except Japan) and at least the European SEGA CD version.
