Is there any way to verify that it is an unused system?

Very small, well if its unopened then its new.

I know a site that has unopened Super Nintendos and Dreamcasts for sale.

But I won't tell you cause I shall get them all myself :P

How do you know they are not opened?

.....................

Good point

Half and Amazon has ton of brand new NES and SNES game.

Half?

Half.com. They're like a cross between Amazon and eBay. I think eBay owns them. I usually check all 3 sites for stuff to look for the best deal. But to answer your "How can you tell?" question... I have no idea. Do you want an unopened one for a collection, or are you going to use it?

Ok, I've never heard of it. I'll check it out. I would like to get unopened systems because I am just anal about buying used electronics. I treat all of my systems like I was using kid's gloves, and I don't trust others to do the same. I lost my NES, SNES, and Sega Genesis, and I want to replace them.

Well I know with the NES the only part that actually goes bad is the 72-pin connector, which can corrode after a decade or two if people are blowing in their games or putting rubbing alcohol or water inside them without drying them. You can get any old crappy NES (that at least turns on) and replace the 72-pin connector really easily, quickly, and cheaply. I did it myself and I know absolutely nothing about electronics. You unscrew some stuff, swap it like LEGO, and screw some stuff back on. Or if you buy one of the refurbished NES's off eBay, somebody just replaced the 72-pin connector and now it's as good as new.

Or you can take a NES or a SNES, mail them to Nintendo, and they'll factory clean them for you and mail them back.

But my 2 SNES's still work perfectly, and one of them even got urinated on by a drunk idiot who was sleepwalking.

I'm not too sure if Sega's still crazy enough to support 20 year old hardware, but Nintendo definitely does.

Good luck! I still need to get a Genesis and a Sega CD when I get some money.