What social profiles rank best

I'm doing some orm and what to know what sites' profiles end up ranking best. Also what are some that you're using that are lesser known.

Currently I'm having success with:
Meetup
Google+
Twitter
Flickr
Slideshare
Quora


Tried and waiting for results
Stumble upon
Hunch
Digg
Delicious
Facebook
Linkedin
Big sight
Four square

What are some other good ones to try?

Thanks

Here's a quick Reddit tip: A lot of subreddits have really high PR, yet don't have a lot of traffic. That means you can get a front page link from the subreddit, on a high PR page, that won't move off the front page for a long time. For example, find a PR 4 subreddit that's vaguely related to your industry. If there are results on the front page from more than a few months ago, chances are great that you can get a link to rank and stick and be a powerful link for you in the long run.

Squiddo is the best for web 2.0 pages. With good content and a link or two, squiddo pages work really well for links. Not exactly profiles, but still very powerful.

If you are trying to push down the negative pages Youtube videos work well, you can usually get 1 and sometimes 2 ranking on the first page for company names.

I'm obviously a big fan of Tumblr, if nothing else because of open they are to different types of content and because of house easy it is to customize everything.

Aside form them though I am big fan of YouTube.