Adsense is not longer as good as it used to be ten years ago, and payments have dropped significantly since, so I wouldn't say it's the best paying ad network, but at least is the most reliable.
Actually there are many other advertising network that seems to be paying better rates including Taboola, Outbrain and Spoutable, which more than plain advertising deliver content excerpts to your site and pays you every time someone is interesting in reading the full articles and click on them.
If you browse major-league sites such as The Huffington Post, you will see they are using Taboola to monetize and not longer AdSense at all.
Even though, if you want to make money from contextual advertising, there is another search engine that pays way much better, but only accepts American-based publishers, for further details visit 7Search.