There are some great ones out there, including a few I would like to be apart of but don't have the time.
One I do like, because of all the helpful people there is
"Forward Motion for Writers". Their description for themselves: If you love writing, Forward Motion is the site for you. Forward Motion's core purpose is to help writers become professionally published. To that end our classes, boards and scheduled chats are aimed at those who are looking for publication. We welcome serious writing hobbyists as well, but our purpose and goals are geared toward professional careers. We do not allow fanfiction posts, and we don't promote self-publishing.
Even though it says no fanfiction posts, in the chat I've talked with quite a few who do write fanfiction.
I've been on the chat with them, especially during NaNoWriMo where we do "word wars" (which are rather fun) to help each other get our word counts, and we run ideas and writing passages by each other. Friday and Sunday they hold "Think Tanks" in a special room of chat where each person is allowed one question, and the others brainstorm for 10 minutes to help them out. I've used it twice to help solve plot problems.
For critiques, I've used
Critique Circle for critiques of original writing. The idea is that you do critiques yourself to earn 'credits'. Then, when you are ready to have something of your own critiqued, you cash in some of those credits to get it on the critique schedule (only so many are put up for active critiques per week). That way they encourage you to 'give' in order to 'get'. I haven't been on there since October, but it was always a nice place, and the forums are also active. They accept all genres of writing, and on the sci-fi story I submitted last year I received 6 really nice critiques that were very helpful.
Darn, I had one more, but the name eludes me.I think Cathrl is apart of it and it has a lot of writing resources and an active community. I'll see if I can find it when I get home tonight.