The best bottom of the central shaft room to me is the Laser Light Room. I know the Tomb of the Headless Kings seems like the more logical choice, but that room was filled with too many flaws. It was way too time consuming, too cramped, and too dark also. It sometimes took up to 30 seconds to complete that room. The Laser Light Room may have been simple, but at least the objective was still unique and the special effects were cool also. Plus, it required
some sort of talent to complete at least. Some contestants like Nick from "Charles Lindbergh" tore the room apart while other contestants like Steve from "Silk Sash" took too long to complete the room.
I might've even voted the Room of Hamonic Convergence if it wasn't broken half of the time.