The most motivation I have gotten from raiding in the past was Topping Class DPS Meters. In TBC The WWScoreboard was the best website to display Rankings, per Boss, per Class and an average Total.
World of Logs has a similar feature, the Ranking Page here. It is a very nice list, but it does not include any kind of filters, yet. As Enhancement Shaman it is often tedious to find the proper page and thus I created and easy way to access the pages. Just select class, fight, difficulty and get directed to the proper Ranking Page.
http://www.myrddin.de/world-of-warcraft/world-of-logs-ranking-links/