Usually, an LP for Nuzlocke goes in the Nuzlocke thread, Scramble in the Scramble, etc. However, I'm a big fan of LP's, so if it's something interesting (Deino hit the nail on the head with his LP, stuff like TPP's youtube videos, or any other fun media also works), then you can go ahead a make a new thread. If you do make a thread for a Let's Play, please keep your LP's all in that one thread for now (think of it like an art thread in Smeargle's). Also, if you do make a thread, make sure you see it to completion. I've seen several people start up and then do nothing, and I don't want that to become a trend ;-;
Hope that helps ^.^