I'm a fan of pacman, but find apt/dpkg acceptable (barely). My biggest two beefs with yum/rpm are that it does not track "explicitly installed" vs "installed as a dependency" (dpkg does, but it's fuzzy), and that when processing dependencies, it does a brute-force recursive crawl instead of building a tree.
Modern Yum does track explicit vs. dependency installs, though this is not very visible in the UI. There are ways to query the Yum database for it, though.
Yum also has an option (disabled by default) to remove unneeded auto-installed dependencies when removing packages (set clean_requirements_on_remove=yes in /etc/yum.conf)[1]. This option does not remove manually-installed packages (though the docs are not clear on this point, unfortunately).
I was fond of Arch when I first heard of it, because back then I was still a BSD fanboy. But as time has progressed I find the use of rc a bit stale and I actually like the initiative of LSB.
