I think intellij is the best option for android. i have used both eclipse and intellij and found intellij is much easier to use with android as compared to eclipse because of these reasons :-
Intellij provides a built-in support for android and you don't have to configure it as you need to do with eclipse.
Intellij gives you auto-lookup feature which is really important for developer like us to increase our productivity. And if we talk about eclipse you have to type each and every method, classname etc on your own. (May be eclipse has this feature too but i never found it and trust me i tried to find it like anything)
Its much more user friendly and easy to use than eclipse.
I hope it will help you and other members of stack overflow to decide which IDE is best for Android development.
My personal choice is Intellij.
EDIT
But there is one thing i love about eclipse and that is visual layout creator. You can use drag and drop technique to create a layout and eclipse will automatically generate an XML file for you just like XCODE.
EDIT
Good News!! Intellij added a new feature which shows how your app's view is going to look like. It doesn't work exactly like Eclipse but it will give you a good idea about your layout.
My personal choice is still Intellij because it helps me to type faster than eclipse.
EDIT
Ok guys these days i am using eclipse juno and found its kind of buggy and slow. So if you still want to use eclipse better stick to some older version. And finally i am able to found how to enable auto-complete in eclipse. Below is a small tutorial.
Eclipse -> Preference - > Java -> Editor -> Content Assist -> Auto Activation
Now put following in the three given boxes
Auto Activation delay(ms) - 0
Auto activation triggers for java - .(abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
Auto activation triggers for javadoc - @#
You are now good to go. Happy coding.
EDIT
As now Google has adopted Intellij for their own Android dev tool, there is no question now about which one is better. Intellij is far far better than eclipse. And i switched back to Intellij and it feels like i am back home!! :D