Perhaps it's just me, but I think the thread rating system is a little weird. Sometimes, I want to absolutely bury a thread, but of course I can't do that, but I can mark it as Terrible.

The problem is that then I've added a little star to the thread, something that now attracts attention and still makes me think it's somewhat valuable, even though I should know that it means this thread is Terrible. How about:

Excellent: 5 stars
Good: 3 stars
Average: Blank
Bad: 1 Thumb down
Terrible: 3 Thumbs down.

Just a thought!