Sinker: A thread that sinks like a stone.
Ringer: A thread that gets a lot of attention, and a lot of responses (in a positive way).
Minefield: A thread that is obviously going to blow up. You can usually tell just by reading the subject line.
Sleeper: A thread that starts out innocent enough, but a few pages in, suddenly erupts into a flame war.
Quote-Fest: When the posts in the thread have so many quotations that the thread contains more quotes than actual messages.
Circle Jerk: A thread whose main purpose is for all the posters to pat each other on the back.
Leg Hump: A thread whose main purpose is for the posters to praise / extol / glorify someone.
[This message has been edited by Blacktree (edited 07-01-2009).]