Text Ads or Image Ads

A question I see a lot is "Which is better with Adsense, text ads or image ads?" and the honest answer is, it depends.
Sometimes a layout will dictate whether you can use text ads or rich media ads. There are certain scenarios where using text ads would break the Adsense TOS whereas using image ads wouldn't.
Another thing to consider is which one would fit better with the placement. Sometimes using one type or the other just doesn't make any sense because it sticks out like a sore thumb rather than a piece of jewelry.

In any event, I've gone ahead and gathered my statistics for the entire year of 2010 and listed each of the Adsense ad types in order of best performing to worst performing for each of the categories Adsense tracks.

Page Views

1. Image Ads
2. Text Ads
3. Flash Ads
4. Animated Image Ads
5. Rich Media Ads

CTR

1. Animated Image Ads
2. Text Ads
3. Image Ads
4. Flash Ads
5. Rich Media Ads

CPC

1. Rich Media Ads
2. Flash Ads
3. Image Ads
4. Animated Image Ads
5. Text Ads

Page RPM

1. Rich Media Ads
2. Image Ads
3. Animated Image Ads
4. Text Ads
5. Flash Ads

Estimated Earnings

1. Image Ads
2. Rich Media Ads
3. Text Ads
4. Animated Image Ads
5. Flash Ads