Ads

Hey. I am looking for a plugin that allows you to place as many ads as you want wherever you want, I can only find plugins that allow for googles ads, or certain types of ads, or only in posts, etc. My client wanted ads along the left and right side of the site, theres like 18 of them. Whats the best route here? Does anyone know of a tag based plug in that I can just insert as many ad spaces as I want for custom ads?