If you ever wanted to get into the Sonic the Hedgehog series, this latest Humble Bundle would be a pretty good place to start. It features a variety of classic Sonic games, as well as some of the more modern ones like Sonic Forces and the truly excellent Sonic Mania.
The one thing the bundle is sadly missing out on is Sonic & All-Stars Racing Transformed, a kart racing game that is more than capable of standing shoulder to shoulder with the likes of Mario Kart. I can only imagine this was done in order to prop up the recently released and somewhat disappointing Team Sonic Racing, but either way, it's a shame to have such an excellent game not featured in this kind of bundle.
My little musings aside, I would still highly recommend grabbing the bundle if you're even remotely interested in Sonic games. Personally, Sonic Mania and Generatios are my favorites out of the bunch, but if you're not willing to spring for the highest tier, the classics are well worth around a dollar and will keep you nice and occupied throughout the cold winter months.
You can find the full list of games, as well as grab the bundle itself, over at the Humble Bundle website. Have fun, and remember - gotta go fast!