The Atari Falcon, the last computer ever produced by Atari, was a powerful yet sadly unsuccessful and OS-crippled beast. Inside the ageing Atari ST case the Falcon sported a powerful 68030 processor, a DSP processor and some vastly upgraded graphic chips. Back in 1992 that was a lot of power, even when taking into account the poor sound capabilities of the thing... Apparently though it was already too late for Atari. You can find out more about the Falcon here and here.
To actually own one you could do worse than checking this Atari Falcon 030 auction out. It's a fully working computer in great cosmetic condition, that comes with 4MBs of RAM and the pretty rare Soundlifter expansion. Seller ships worldwide.