My top whatever: 1: Adblock 1: Flashblock 1: Javascriptblock (noscript) 2: Cookieblock (cookie manager) 3: Cacheblock (cache manager) 4: Bookmarks and history manager -- The 9 thumbnails are very helpful, but I use chrome on two computers, I want my bookmarks and history to be synced.
To me, the best bookmark sync plugin is Foxmarks. It works currently on Firefox; beta versions are available for IE and Safari. It has a very responsive developers team too.