I was impressed a few years ago, when they came out with the three foot long Star Destroyer that was - at the time - the biggest Lego set ever created, weighing in at 3104 pieces. But once I bought and assembled it, I was a little disappointed at how flimsily constructed it was. I eventually sold it and replaced it with the smaller smaller Star Destroyer that is much more sturdy.
Later, they raised the bar again with the two foot diameter Death Star set, which took over the title of biggest Lego set ever, at 3447 pieces. The Death Star was only slightly more stable than the big Star Destroyer, but it was just so damned impressive on the shelf that no one noticed. I have this at my desk at work, and man is it a conversation starter.
Well, now they've done it again. And this time, they're doing it in style. The new Ultimate Collector Series Millennium Falcon is nearly three feet long, built to the scale of the Lego minifigs, and weighs in at a hefty 5195 pieces! Yes, it's has an equally impressive $500 price tag, but that's the same price point as the QMX Serenity model is going to be, and this is the Millennium Fucking Falcon, and it's made of Legos! It is also made of awesome.
This goes above the QMX model on my fanboy wish list, although still slightly below the custom-made Serenity Lego model that I desperately wish they would mass produce.