If you had a Sega Genesis back in the day, you should check this out. This game has 40 Genesis games on it. Just getting Streets of Rage 1 , 2, and 3 would've been enough for me, but you get 40! That's some serious value!
In addition to the 40 Genesis games, there's also 9 unlockable games like the arcade version of Altered Beast, Space Harrier, and Shinobi. The fact that I can remember playing Shinobi in the arcade really makes me feel old.(Do arcades even exist any more?)
I love playing these old games. They bring back a lot of memories and they're still fun.