If you were going to an island and could only take one system, would you take a Playstation 1 or Sega Saturn?  You would have every game in it's library including Japanese releases. 

I would take the Saturn.  I like the 2d fighters and Working designs classics.

Gmsnpr really hit it on the head. In high school when I wanted a car I sold all my stuff, and only recently have I been able to afford to buy it back.  I associate a praticular game with a point in time.  Double Dragon 2 was a 10th birthday present so I didn't hesitate to buy a sealed copy on Ebay.  As I've gotten older I've enjoyed finding great games on clearance and I've given up on trading things in, or selling them on Ebay.  If you can make a game feel like a favorite song and let it take you back it is a lot more fun.

Barbie Horse Adventure for Xbox?  I was embarrased until Microsoft made it backward compatible with XBOX 360.  That must mean others find it enjoyable as well.

Just picked up Street Fighter 2 for Super NES.  Completely sealed for $20.  Not a bad find.