I would want to find RoboCop 2 for the NES. I used to play that game all the time at my dads' place when I was younger, so it would be a nice nostalgic trip for me.
As for what I wouldn't want to find... I would have to say the Lego Star Wars games (more specifically, Lego Star Wars II: The Original Trilogy). Since they're much lighter-hearted versions of the movies, they don't capture the essence of the original theatrical releases, and the gameplay itself is slow, mediocre platforming at best (occasional unresponsive jump; falling into a pit of some kind happens too often due to some strange camera angles and annoying physics system).