I've decided that I will start functional programming with Haskell. I've delved deep enough into the Learn You a Haskell for Great Good! tutorial to really turn back. In comparison, the available "starting" Erlang documentation seems daunting.
It also helps that Real World Haskell, published by O'Reilly, has gotten rave reviews and won the 2008 Jolt Product Excellence Award. (Why this isn't on O'Reilly's product page for the book, I don't know.) Remember what I wrote about books?
This is not to say I've written off the other languages I was looking at. Erlang, Scheme, and Scala are definitely leaders for the next language. In fact, before starting with Haskell, I want to take a short detour and read The Little Schemer first. I've heard good things about the book and since I'm about to delve into functional programming, I want to read it. The worst thing that can happen is it turns out to be a waste of time and I'm sure it won't be.
(Edit: I just noticed that the title of this article was incorrect. This has been corrected. Sorry for the issues.)