Okay, so this may not be everybody's idea of stress relief, but Lifehacker has found a definitive guide on how play games from any Nintendo system on your computer. In short, programs called emulators act as the different consoles, allowing you to play games you download from various places online.
Many years ago, I used a Sega Genesis emulator to play Altered Beast, one of my favorite old games. I love it. Sometimes gameplay can be a bit buggy, but rest assured: the ROMs (the game files) you download are copies of the real thing, not some cheap knock-off.
As you'd expect, there are a few legal issues involved in all of this, but far less than the ones surrounding your music files and where and when you can play them. Read this if you're concerned, but it's really not a big deal. I mean seriously, do you think someone is going to sue you for playing Excitebike?
Incidentally, while researching for this post I found nintendo8.com, which allows you to play Nintendo games and more with no download required (including Excitebike!). Search for your favorite old titles from any system on Google and you're bound to find similar sites.
Hopefully this will whisk some of you away for a few hours... and that's what stress relief is all about!