Here's another "plug and play" type device. It's pretty much the same thing as the red one above, but it has different games. As you can read, there are 6 games, but they've chosen Sonic to highlight the box.
This really shows the popularity of Sonic, as here is a company trying to sell a non-100% Sonic thing as a "Sonic Item" by plastering him all over it. You actually just get Sonic 1, but then also Altered Beast, Golden Axe, Kid Chameleon, Flicky and Mean Bean Machine. Flicky (difficult to get a hold of) and Mean Bean Machine are somewhat-Sonic themed, but not quite.
These things are an all-right way to try older Sonic games, if you didn't want to buy a compilation (Like Sonic Gems) or something.