Unfortunately, there is no such alternative which would be close Google Adsense. If you're looking for Bitcoin advertising networks, there is long list of it:
https://bitcointalk.org/index.php?topic=5196251.0But unfortunately, best networks have quite big requirements, such as Alexa rank, so it's not good for new website.
I'm not very familiar with fiat advertising networks, I can only mention few names which is known for me, like Media.net or PropellerAds.
Another option may be various affiliate ads, such as Amazon.