When I first ran across CMake being used, I thought "Oh no, another build system!" That means I need to install some lame software to build this thing.
After seeing it used some more and reading about it and thinking about alternatives, I've changed my tune.
If you need to build C or C++ (can't speak for other things), and you want to be cross platform (though I haven't tried cross-platform yet, it does seem promising), and you don't want too much pain, I currently recommend CMake. I haven't tried every alternative out there, which is why I don't give a stronger endorsement. But from what I've seen so far, CMake rocks.
And it definitely beats writing Makefiles (and I'm scared of autoconf, too, for some reason).