You can get up to 12 Sonic gamesincluding classics like Sonic CD as well as new games like Sonic Mania.
I've played Sonic Generations and Sonic & All-Stars Racing Transformed and found them to be really good. They both have over 90% positive reviews on steam as well.
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Where your money goes is up to you - split if freely among a charity of your choice, SEGA and Humble Bundle (you can leave me a tip as well, if you want).
I suggest supporting charities that have been evaluated by charity evaluators such as GiveWell and have shown to make very good use of the funds they receive - not only in terms of efficiency, transparency and accountability, but also with respect to the impact they have on the world.
Examples for effective charities you can donate to through Humble Bundle are the Against Malaria Foundation, the Good Food Institute, Evidence Action and GiveDirectly.
Or you can support meta-organisations such as The Life You Can Save, Animal Charity Evaluators or the Centre for Effective Altruism which conduct research on how to help more effectively and raise money for effective charities.
Meta-organisations can leverage your donations - The Life You Can Save, for example, raises about $13 for their recommended charities for every dollar you donate.
-> Let's play and support charities! 
(only available until the new year)
(picture from Pixabay)