My perfect build requires a house upgrade... but...
it all starts with a nice big bong cooler as an artistic water feature (using clear pvc pipe & probably some sort of aquarium for the reservoir, I'm thinking a seashell diorama or some other hanging feature inside the evaporation pipe). To cut down on maintenance we'll need some good design, dust filters for at least air inlet & probably outlet, a silver kill-coil, & an auto-refill valve fed by a reverse osmosis water purifier (one with two outlets so I can also use it for drinking water).
Ideally that part of the build will be isolated in the guest bedroom (or workout room), possibly with a NAS system. A few holes drilled in the wall will allow tubing into the room I have the computer. The whole point of that setup is to have kick-ass slightly sub-ambient temperatures for water-cooling, yet also have an art feature & a nearly silent computer system (all cooling noise eliminated by a big-ass wall).
The tower itself will have (most of the time) only ONE source of sound - the case fans themselves set to very low. Near silent.
That case will probably be a Fortress 02 with one of the three fans removed (sound dampening, I like the looks) or the Raven 03 (bigger, more modern design). Not sure on window. Why those two cases? Well, relatively quiet case fans & I like having the I/O panel on the top. Both cases will probably have to be modded (aka, take a drill or hacksaw to it) to allow watercooling tubing in & out.
PSU: Seasonic Platinum 1000w (not least because of the hybrid fanless feature - much of the time the fan on the PSU will be off.
DVD-burner: some Asus. Relatively quiet as DVD-burning brands go - but of course this potential third source of noise will usually not be used & thus silent.
SSD: 500gb, probably a Samsung 840 (no HDD, no case vibration or noise). Additional storage through nas.
Video Cards: 3x 7970 (silent because water-cooled. Also, overclocked to high heaven, because water-cooled).
Asus z77 workstation board (variety of reasons)
i7-3770k (obvious choice & water-cooled, so overclocked to high heaven. Probably too lazy to de-lid though)
Sound Card: Sound Blaster ZxR
Speakers: Creative T40
Headphones: Audio-Technica AD900
As for monitor setup - a little unusual, but probably a PLP 1200x1600, 2560x1600, 1200x1600 setup. Not an ideal eyefinity gaming setup (actually, can't run eyefinity at all - damn you AMD & Nvidia drivers), I admit, but I think this would actually be the best setup for me productivity-wise. Might go with massive big-monitor eyefinity though.Edited by MisterFred - 2/16/13 at 8:29am