yuyuh

Insert ads in your post at the place of your choice in a single click. Adds buttons in your toolbar to place ads while writing your post. Now Inserting ads in your post is even simpler than underlining a word. All you need to do is put your Google Adsense code into the boxes provided and then click the corresponding button in tool bar to show the ads at place of your choice in post. Remember showing an ad at the right place in your post can result in much better revenue as compared to placing it randomly or some fixed place. You can also use ad-codes from other providers to show with adsense.
<h3>Note</h3>
A link from your blog to www.yuyuh.com is highly appreciated. Please note that use of Ads Code 3 & 7 also adds a powered by link in the bottom. If you don’t want to place this link in your site, use only other codes. Other codes will show only your ads and nothing else.
<h3>Demo</h3>
A live demo of the plugin at work can be seen here.
http://www.yuyuh.com/w/2011/08/insert-adsense-version-2-demo/

Insert Adsense

Adds buttons in your toolbar to insert upto 7 types of ads on any side or inbetween your post content.

Thomas Maier

WPAds is a free plugin for showing and managing ads on your WordPress site. It works very similarly to other ad servers, but because of its limited functionality, it is much easier to use.
<blockquote>
Please read before updating
This is a fixed version of WPAds which was not hosted on wordpress.org before. 
 I updated this plugin to work for existing users with a newer version of WordPress, but would suggest new users to use <a href="https://wordpress.org/plugins/advanced-ads/" rel="ugc">a better ad management plugin</a>. 
 Please, don’t update if you don’t use at least WordPress 4.7.
</blockquote>
The main concepts of WPAds are zones and banners. After creating zones you can insert these ad positions in your template or in your posts, e.g. as positions for ads in header, sidebar or content. Than create some banners, paste the ad code you want to display and assign them to your ad zones. WPAds will serve your ads randomly to those positions. The rotation is based on a variable weight of your ads.
WPAds can show different ad formats (HTML, JS; PHP, Image ads) and support ad networks like Google AdSense, Yahoo Publishers Network, Amazon or Chikita.
Features:
<ul>
<li>shortcodes for injection into posts and templates</li>
<li>unlimited ads</li>
<li>unlimited zones</li>
<li>ad rotation</li>
<li>ad weight</li>
<li>impression counter</li>
<li>max. views per banner</li>
</ul>

WPAds

WPAds is a simple and light weight ad manager for WordPress.

Insert Adsense vs WPAds