As you know, the best is hdbits. The altinatives are awesome-hd, bit-hdtv, hd-torrents. Those are invite only but not that hard to get in.
This man know his stuff. Plus depending on your connection its going to be harder to seed back. You will be downloading much larger files so ratios can be a pain.Just a friendly tip, usenet is actually much better than any HD site. Take these words of wisdom from me, shell out some money for what you will inevitably realize is the best thing.
You can assume that I don't know what I'm talking about and am trying to force you to waste money, or you could go try what I told you and never look back. (Yes, it's a guarantee)
EDIT: If you're hardcore bent on using a tracker for your HD needs, know now that the best are HDChina/CHDBits right after HDBits.org