Im releasing my app on Google Play within a few days and all I lack is ads for the ad-version, so I was wondering what you guys think is the best one to use? 
I have only ever used Admob, so I can’t make any comparisons, but I want to give some important info about Admob.
When their animated Adsense (the google ads word based adverts, not the banner ads) are used, they seem to cause a significant drop in FPS. In my game I noticed a drop from consistent 60 fps to around 44. You can read more about it here:
http://www.badlogicgames.com/forum/viewtopic.php?f=11&t=12558&p=56049&hilit=admob#p55955