SMILE won't work

[Seeko]

When I try to load a ROM, it tells me that it's PAL and won't work with SMILE. what do I do to avoid this? I've tried multiple emulators. Can tell me the name of one that works?

[thedopefish]

Just like the error says.  You're trying to use a PAL rom (that is, one from the European region), but SMILE is only designed to work with an NTSC rom (that is, one from the US or Japan regions).  Acquire a copy of "Super Metroid - (JU).smc" and it will work.