This is an excellent tracker, ever since I'm registered almost use by more than HDBits.org.

The internal groups are top notch, the major strength of the tracker, the community is active and friendly.
Awesome-HD has some internal encodes released by groups such as FoRM, HiFi, FTW-HD, D-ZON3. These groups actively upload on AHD and this is a good place as any to find their latest encodes.

After HDBits, Awesome-HD is one of the best.