I was just looking through some old Sega Genesis games I used to play as a kid, and I found my original Sonic the Hedgehog has a 'Not For Resale' sticker on the box (under the plastic) and on the cartridge. Being older, and now fully appreciating the meaning of those words, does anyone know what it's worth? Note: it plays perfectly fine (no manual), and I assume it's the same as retail, I've never gotten a chance to compare it.
I don't want to spoil the happiness, but... are you sure it's not a "bundle" version? (ie. same as retail, bundled with the console) These generally have the NFR label (at least that's the case for other consoles, not sure about Genesis).
For those who aren't aware the concept of a "Not For Resale" isn't to denote something super special it's just a way of making sure retailers can't pull the bundled game out of the consolebox (or what have you) and stick it on the floor with other copies of the same game. SEGA failed to do this with the Smash Pack and retailers pulled it like mad. Occasionally an odd NFR title turns up because it was labeled to prevent sale of a demo cart or something loaned such as the Pokemon distribution carts used at GameStop and TRU. Doesn't stop them from being sold in non-retail channels obviously.
The sonic NFR seems to be more common than the regular sonic. It's kind of like Wii Sports, it came with the console. It's not really special or worth a whole lot. Sorry.