I've been using AdSense on this site more-or-less since the beginning. I try to keep its presence unobtrusive, and I think that that shows in the results. My click thru rate is hovering around 0.75%, which is roughly one click for every 133 page views.
I've started to look into improving those numbers, but so far I'm not seeing anything that won't make its presence significantly less welcome. If you're reading this and have had better success with AdSense, I welcome your comments below.