I remember when I was 5 or 6, we had an old Nintendo Entertainment System hooked up to the TV (someone gave it to us because we couldn’t afford cable), with one cartridge — Super Mario Bros. with Duck Hunt. Now, nearly 10 years later, I wanted to play them again. Either I could try to buy a NES (which could get expensive on eBay!) or use an emulator on my computer.
So far, I’ve been using Nintendulator (an open-source NES emulator) which I’ve found very good (and it’s also said to be extremely accurate.) So you download your ROM, load it in, set your input devices (tip: Never resize the window using the edges if you’re using the Zapper. It’ll make it not work), then CPU >> Run. And enjoy the old games!