As you're probably well aware, emulation is a fantastically convenient way for us to play our old games but it does suffer from a few problems. Many of those issues surround the legality of playing copies of ROMs downloaded from the internet, a grey area which has been debated for decades by people in no position to give legal advice.
The Retrode 2 skirts this issue altogether, acting as a USB-compatible port for your Super Famicom/Nintendo and SEGA Genesis/Mega Drive cartridges. A cartridge slotted in the Retrode has its ROM files mounted as virtual files on a USB drive which can be accessed by your favorite emulator. It also features ports for connecting your original SNES and Genesis controllers, which are mounted as HID-compliant devices.
It's also not terribly cheap. The one US-based distributor for the product, Stone Age Gamer, is currently accepting pre-orders at a price of $84.99 (free shipping). In Europe, you can snag one for a little over €70 direct from Retrode. Still, if you want to feel good about yourself when you're playing emulated games, is that really too much to pay for peace of mind?