Ever since I saw a most awesome Merckx in fat Columbus with ovalised lugs on the down tube, I've hankered after one... but on visiting the Merckx site, I see they've apparently eschewed steel! Ye Gods.
Prolly the ultimate machine I can think of were twenty Litespeed Blades built for an American team (the name escapes me; they had green and yellow livery) about ten years ago out of 6Al4V sheet.
Those frames were worth something like US$20k a pop.
But I'd be stoked with a TCR or something.