There is also zzos. (Full disclosure: I wrote it). It only decompiles the actual resources, not the dex part (baksmali, which I did not write, does an excellent job of handling that part).
Zzos is much less known than apktool, but there are some APKs that are better handled by it (and vice versa - more on that later). Mostly, APKs containing custom resource types (not modifiers) were not handled by apktool the last time I checked, and are handled by zzos. There are also some cases with escaping that zzos handles better.
On the negative side of things, zzos (current version) requires a few support tools to install. It is written in perl (as opposed to APKTool, which is written in Java), and uses aapt for the actual decompilation. It also does not decompile attrib resources yet (which APKTool does).
The meaning of the name is "aapt", Android's resource compiler, shifted down one letter.