There are plenty of great PDF reader available for android devices, but I still find that some load pages (particularly large, full color pdf's of magazines) faster than others. Out of all I have tried, RepliGo Reader currently stands out as the fastest. On top of providing a great reading experience, RepliGo Reader also features some great extra capabilities, such as the ability to annotate and draw all over documents (ala the Galaxy Note).
If you want a reader that simply works, and does so quickly, then get RepliGo Reader.
In the words of the developer:
View, annotate and fill out forms in Adobe® PDF format while on the go!