Netvibes introduced a whole new set of customization features. I have been using iGoogle for the past few months because I am in love with Google. I have used MyYahoo, MyMSN in the past too, not lately though. Now with Netvibes giving you the option of adding new themes and wallpapers, I like it a lot. I know MyYahoo lets you add content and has multiple pages, but I like those little gadgets that you can add to iGoogle.
see netvibes theme choices
I think Netvibes is taking over all of them in looks as well as functionality and ease of use. It lets you cram a lot of the universe on just one simple page, all at your finger tips, hundreds of feeds, emails from loads of different clients, to-do lists, and even chat-clients, all can be reached via your home page. Guess I am going to be using netvibes more than iGoogle these days.
See more at netvibes blog
What do you use and why?