Out of these listed here, by far my favorite is Zeitcoin... it seems to have the most momentum behind it, and thus has (IMO) the best chance at becoming a workable currency (or "barter resource" as the Zeitgeist Movement might prefer to call it).
Other than these, I really like Dogecoin because of the community and the infrastructure that has already been built up around it (again... workable currency). I also like Mooncoin (there seems to be some sort of unofficial alliance between the Mooncoin and Dogecoin communities, at least those on reddit), and I like Teslacoin (from the less practical standpoint of being a Nikola Tesla fan and the aesthetics of their logo design).