Here are a few networks
https://99bitcoins.com/bitcoin-ad-networks/There are also 1 or 2 lists posted somewhere on bitcointalk but you will find almost the same names listed.
I only used A-ads.com myself so I can only comment about it. It's perhaps the first ad network-oriented bitcoin. I used it in the early days. We didn't even need to create an account (it's probably still the case) and the payments are automatically sent to your wallet once you reach the minimum payment. It's perhaps one of my first bitcoin transactions received =)
I found their system pretty innovative, especially from an advertiser's point of view. As publishers, if an IP has already seen a banner during the day, you won't be credited if the same IP visits your site for the first time of the day. A unique IP is considered unique for the whole network, not for your site.
Several persons said it's a low-earning site but that's because their system is efficient for advertisers, and the publisher's traffic is not of good quality. I earned thousands of dollars (or rather BTC) with them and it has been one of the most interesting networks I used, and believe me, I used so many CPC, CPM, CPA over the years with all the format possibles
Later I wanted to give it a try to Mellow Ads, it took them over 6 months to approve my website, so I gave up the idea to use it well before lol.
