Best Way to Customize Leopard's UI?

[Beegolof]

What are some of the best Mac OS X Leopard compatible tweaking/customizing apps? I'm looking for apps that will change the look of Leopard or will add new ways to navigate through my files. Basically something to make it look more unique and customizable. I've found a few but they were very hard to find. I was wondering if there were any other apps around for this.

Thanks in advance.

 

[Watabou]

For changind icons+docks: Candybar

For navigating: Quicksilver