Recs.
Updated
SpecsUpdate
Pros
Pro Fast and simple package management
Pacman has performance advantages over apt-get and yum in both database operations (thanks to being written for speed) and download times (by virtue of using better mirrors than other distributions tend to select by default). There are also fewer default repositories to download from, and all package management is combined into one tool instead of being split into dpkg, apt-get, and apt-cache like on Debian distros.
Pro Excellent documentation
Arch's goal of simplicity means there's usually one preferred way to get things done - through organized and well documented configuration files. This focus, combined with the community's recognition that configuration files can be intimidating, has resulted in excellent documentation that's accessible to newcomers, and very instructive about how Linux actually works. The documentation is often so thorough that, when searching for solutions to problems while using other distributions, such as with video card drivers, oftentimes you'll find the most effective solution in the Arch Linux wiki or on the forums.