Mega Man (1)   Mega Man2   Mega Man3   Mega Man4   Mega Man5   Mega Man6   Mega Man7   Mega Man8   Mega Man9   Mega Man X   Mega Man X2   Mega Man X3
Disclaimer:
You must delete any ROM(s) you download within 24hr.
(If you do not own the original game, that is.)

If you do not have an SNES Emulator (required for MM7 and higher)
Go to http://www.zsnes.com/ to download the best emulator I know of!