cranky
150_comms is a great place to find all kinds of fanfic challenges.It probably doesn't list every LJ fanfic challenge, only those that the Comm owner has come across and/or other Comm owners have advertised, but there are current 449 challenges listed. They are divided firstly by 'Traditional Themed Communities' and 'Weekly Challenge Communities', and then by the number of stories in each challenge.
Be warned, you can spend quite some time perusing all the goodies you could sign up for :-)
