Like TSCC, awesome game-changing cliffhanger we never got to see resolved. Alas! Thank goodness for fandom :P

I read the first episode of a virtual season (virtualdarkangel.com), which wasn't bad? I haven't read more because I'm doing it in French, which I find a bit more challenging than I'd like to admit :P

There are actually canonical books as well, which were published after the series was cancelled! Valjean's fanfic (and oh, it's long, Max/Alec, and often crosses with Supernatural) picks up from where they left off.