If I wanted a quality computer built for me, I would order it from Digital Storm (
http://www.digitalstormonline.com/) . They use high quality parts and their machines look cool. They also offer excellent cooling solutions (including H20)and will overclock to your specifications. I find their prices quite reasonable.
For under $3000, you could build your own computer. This is what I am running now. Prices are rounded to the nearest dollar....
Case: Lian Li PC-65 silver $120.00
PSU: Thermaltake Toughpower Modular 700w $160.00
Main board: Abit AW9D (Intel 975X) $170.00
CPU: Intel Core 2 Duo E6600 2.4 GHz $318.00
HS/F: Thermaltake Big Typhoon VX $55.00
VGA: EVGA 8800GTX $580.00
Memory: 2 x 1 GB Crucial Ballistix DDR2 800 (6400) $280.00
HDD: 2 x Western Digital Raptor 150GB 10K RPM $220.00 each ($440 total)
Optical #1: Asus DVD ROM/CD-ROM drive $20.00
Optical #2: Asus DVD burner $36.00
FDD: Mitsumi 3.5 1.44MB FDD (only needed to set up HDDs in RAID) $6.00
OS: MS Windows XP MCE w/ SP2 $110.00
Anti-Virus: Kaspersky Anti-Virus 6.0 $55.00
Input: Logitech MX3200 Laser RF keyboard and mouse $73.00
Monitor: ViewSonic VX922 Black/Silver 2ms LCD Monitor $270.00
I think that's under $2500.00.
Around 11,000 in 3DMark06 (modestly overclocked: FSB @ 322 --> CPU 2.90 GHz). Good enuf for most games even at extreme settings.