I really love the fact that I can change profiles depending on CLI prompts. So, when I SSH into a server the background color of my terminal changes to blue. When I change to root but background changes to white. This, along with banner support, helps me keep track of where I am and what user I'm currently using.

This functionality may be available in other terms, but iTerm just seems to nail pretty much everything in one package. I just wish it was available for Linux.