The best feature of homebrew, in my opinion, is that it doesn't require sudo for installation of any package -- in fact, it complains if you try to install something with sudo. Contrast that, say, with npm -g. Most npm -g installs will fail without su, unless you are willing to spend a half hour reconfiguring where dependencies install--pretty fucked in my opinion, as you could potentially install something really nasty.

Now, many package managers like apt-get use curated databases for their packages. But in my view, this just is not enough. Homebrew's respect of the user's system is just superior.