Wow, this is getting a bit out of hand.
Just because the system is for you, doesn't mean it is a product for most people. If you want to emulate (ie: not run on original hardware), you can use devices that have better compatibility than this device, are cheaper (or you already have one, like a PC), don't have the clutter and cost of buying used games, and have all the controllers you just mentioned via the power of USB. In the case of modded Xboxes, you have plenty of options for classic gaming controllers as well (I won't get into that unless you want me to...).
If you want original carts on original hardware, this isn't really the device for you either, and there is really only one choice. You have to want the flaws of running roms on iffy hardware with tons of bugs, while using real carts and controllers. Seems like a weird half-way that feels more of a compromise than it out to be.
Not counting the power base converter, as this doesn't come with it, if you go out and buy a Gameboy Advance SP, an NES, a SNES, and a cheap Genesis, it'll cost pretty much the same amount as this, and they come with their original controllers.
I personally am not trying to "call it junk or trash", but there is PLENTY to be critical of here. The controller it comes with complete junk, you have to buy (or own) controllers for the systems you don't own (if you're buying something like this you wouldn't own the real systems, after all...), you're emulating on iffy hardware to TONS of issues while having to deal with the collectable used game market which isn't cheap, and the system itself is very pricey.
I'm glad it fits people's wants and desires, like you, but this is NOT a system for most classic gamers. MOST will find either original hardware or pure emulation to be the best for their need, as each side has less compromises, depending on your tastes. The only positive, frankly, I can come up with is the high def output. But then both emulation and simple RGB mods take care of that. Once again making this feel like a compromise of each side instead of the positives of each side.