Favourite chess GUI?

Hi,
I am just curious what is your favourite chess GUI and what are it's advantages/disadvantages. Is it Fritz, Chessbase, Aquarium, Hiarcs, Shredder...?
Feel free to share your experience :)
Thank you!

I like Hiarcs Chess explorer and chessx gui's.

WinBoard / XBoard. Because it presents different kind of info's in different windows, so that I can close all the distracting stuff I don't want to see. And easily tile my display with the stuff I want to see, when I run multiple instances of it.