r.a.d.rotator is a multipurpose component for DHTML content rotation and personalization.

Goggle Conversion Tracking Control allows you to add Google Adword Conversion Tracking to your website.

SmartASPAd is a web-based ad management software that helps website owners or webmasters plan and manage their ad campaigns.

AdSense is a free Asp.Net Google AdSense Control.

PageSense for Google AdSense is a free ASP.NET Server Control for Google AdSense with Visual Studio.Net Designer.

PopUnder Ad Controls allows you to add professional quality annoying pop-under ads to your ASP.NET pages

AliaWeb Power Ad Manager is a hi-performance advertisement managing solution for a Microsoft IIS server with a special client for Active Server Pages/ASPNet.

Google AdSense control for ASP.NET - fully customizable AdSense control

ASP.NET Ad Server Management Control can get fairly complex depending on your websites requirements, but for starters the built in ASP.NET Banner Management will suffice until you out grow its limitations.