Which Adsense format should I use on my site?

Make sure you choose the Google Adsense format that blends well into your site/blog. Don't overdo it & put way too many links. You are probably thinking the more links the increased likelihood that someone will click on the link, but the opposite is usually true. If a visitor visits your site/blog only to be inundated by ads, the likelihood that the visitor will stay on your site dramatically decreases. The visitor is looking for good content/information about the topic they are interested in, they don't want to see a slew of ads.