Can you recommend a banner exchange?

Can anyone recommend a good quality banner exchange? Anyone had any success with banner exchanges? Can you get control over the types of ads that appear on your site?

My site sells unique web site templates so I don't want to have adverts for home insurance or other totally unrelated products appearing, nor do I want dodgy "Your a winner!" type banners.

Alternatively, does anyone know of a site which allows you to find sites to exchange banners with (ie. "one to one" rather than a banner exchange network)?