Hihi! Looks like you are new, you can't ask where to get roms here or you get kicked in the nuts on your way out the door. As for your problem: nemu crashes when you open a rom, correct? What are your system specs? Did you test the rom to see if it is valid? Do you have up to date drivers/directx? If you can't answer or don't understand any of these questions, I reccommend hanging around a bit and learning before you ask questions.
Oh, and have you tried multiple emulators and not just nemu64...?