I don’t want to write a full review, because I personally find them to really ugly-up Safari’s clean interface, but if you do like Favicons in your Bookmarks bar, Tab bar or both—Faviconographer will fix what ails ya. See the image above for what Daring Fireball’s John Gruber and so many others call an improvement or necessary feature.
Download Faviconographer. Enjoy your uglified Safari interface.