But, at least when it comes to the Nintendo, I've never actually beaten any game but one. That game was The Legend of Zelda: Majora's Mask. I think I actually beat it twice. (I take it back, I've beaten two Nintendo games in my life. The other being Lego Lord of the Rings for the Wii. Which I've also played through twice.)
I owned several games for the N64. But I always came up against one boss and got stuck. Or one set of challenges my skills weren't up to snuff for.
Currently, I own several Wii games, including two Zelda titles, that I haven't beaten. I'm replaying Ocarina of Time and Majora's mask now in the virtual console, too. Which puts me at four active Zelda titles at one time.
So, yeah, I enjoy video games but I'm a total wannabe gamer. I'm a nerd in many other ways, though, so this lack is perhaps compensated for in some degree. I'm keeping my nerd card for now.