I like RetroUSB’s AVS system. It’s awesome for playing real carts of NES & FAMICOM in 720p HD. It’s FPGA, which emulates the original NES Hardware. You can also connect the Famicom Disk System too. It’s a ‘cheaper’ alternative, than getting the Hi-Def NES upgrade on your still functional original NES. However, it can’t play Zapper games, since it only has an HDMI output.

If you have 500 bones, you can buy the Analogue NT mini, which can play Zapper games, due to having all the different outputs.