I have Final Fantasy and Dragon Warrior I, but I guess I'm not willing to give them up for sentimental reasons even though I'll probably never fire them up on a console. I got started on RPGs because of those titles and I won a Nintendo Power contest that sent me a copy of Dragon Warrior, with special guidebook and poster. On the other hand, it's a shame to just leave carts lying around collecting dust that you'll probably never use for ages and would settle for an emulator anyway if you ever got the itch. I do wanna get that flashcart for SNES and in exchange give up most of my originals I'm not attached to in that case, but I hadn't thought about it for NES though. I like owning the original gold-colored "The Legend of Zelda" cart for example. That's history right there!
Anyway, I take it these games were some of what was lost because of your brother's thieving that you want back ?