From what I remember, the default terminal emulator on OSX does not even allow customising the color palette! I was able to only change the foreground and background color, and forced to stick to one of the predefined themes for the rest. On the other hand, I doubt iterm2 can achieve the flexibility and customisability of urxvt, which for me is still the #1 terminal emulator. Just my two cents to add to the discussion :)
> From what I remember, the default terminal emulator on OSX does not even allow customising the color palette!
For what it's worth, at least in Mountain Lion you can change the ANSI palette in Terminal.app. That said, it would never have occurred to me that this is something someone might want to do :).
> From what I remember, the default terminal emulator on OSX does not even allow customising the color palette! I was able to only change the foreground and background color, and forced to stick to one of the predefined themes for the rest.
This certainly hasn't been true since at least 10.7, and I think for longer than that.
That's really not true: You can completely customize the terminal.app colors (background, foreground, cursor, selection highlight, ansi colors, etc.), the window transparency and blur-effect, both for active and inactive windows. You can save your customizations as themes.