With the number of online games out there that can be played on the web, I'm not sure why there is a need to keep the old consoles.
Today, I played some old classics I had not played in a while, even though I own the games. I was just easier to load them on the computer. There are quite a few sites. On just two of them, I found the games I was wanting to play:
Super Mario Bros:
Donkey Kong Jr: