Origin, Maingear, and Digital Storm are all great boutique vendors, but Falcon Northwest is my favorite. It was the first true PC custom builder for gamers on the cutting edge, inspiring all of the others you mentioned. I last month (May 2013) purchased a Talon system from it, and have been very satisfied with the machine. At the same time one of my local friends built his own machine, and he had an issue where one of his four memory sticks wasn't being recognized, so he had to spend several days diagnosing his machine before discovering that his motherboard was to blame, and he barely made it under the 30 day Newegg replace-or-return policy by that time. In my case, Falcon ran an extensive 3-day torture test before declaring the system stable and worthy of being shipped. It arrived at the promised time (just over 3 weeks from when I ordered it), and I've now been using it for just under 3 weeks without any issues whatsoever!
I paid a total of $4230, which includes standard shipping and an extended 3 year warranty which I doubt I'll ever have to use. My system specs are: Falcon Northwest Talon with Windows 7 64-bit Professional, Asus P877Z-V Z77 motherboard, Intel i7-3770K 3.5 GHz overclocked to 4.2 GHz, Asetek 120mm liquid cooler, 32 GB (4x8 GB) of Crucial DDR3 RAM 1866 MHz, EVGA Geforce GTX Titan with 6 GB of VRAM, Sound Blaster Recon 3D Fatal1ty Champion, SSD Crucial M4 512 GB, Western Digital Green 3 TB, 2 Asus DRW DVD+- optical drives, Silverstone 1000w modular, integrated LAN, Steelseries World of Warcraft mouse, Samsung SyncMaster 940BW, and a Microsoft Sidewinder x6 keyboard. The only parts cannibalized from my previous system are the mouse, keyboard, and monitor.
I would have purchased a Tiki instead, but it hadn't any room for a discrete sound card. I'm sure the onboard sound is fine for its default small form factor motherboard (the Asus P8Z77-I deluxe), but I really wanted that separate Sound Blaster card. In addition, the Tiki could accomodate a maximum of 16 gigabytes of RAM, and I really wanted 32. Finally, it can't accomodate an additional video card. I purchased just one Titan for my rig, but am open to purchasing another later on should I grow more comfortable with the concept of SLI. For now, all of the games I play (including Elder Scrolls: Skyrim, Battlefield 3, World of Warcraft, Metro Last Light (got it free for ordering an NVidia card) and so on) are run at maximum settings without a hitch!