The latest "Best of 25 Years" stamp set is the Best of Brides & Babies. All of the stamps released so far are still available until March 2014. Doesn't that sound so far away? It will be here before we know it.
I have made a page where you can see all of the stamps available so far and will update it as they are released. There will be a link from my sidebar to the page so you can check it whenever you want. Go to the "Best of" page.