There are lots of tutorials out there that try to explain how to deal with transparent gifs from Photoshop but none really explain properly and simply how to do it. 

 These settings work with white background perfectly, for a colored background use the Matte settings, it even works pretty good with gradients, get the eyedropper tool to grab the basic color, works very well.

But here it is, when using these settings all gifs show up as perfectly transparent everytime no matter the complexity of the image:

http://www.xuzo.com/transparent-gif.gif

 The answer is there