Here are the specs for PC:

PC MINIMUM SYSTEM REQUIREMENTS:

Operating System: Windows XP SP2, Windows Vista
CPU Processor: Intel Pentium D (Dual Core) 2.8GHZ or AMD Athlon 64 3500+
Memory: XP - 1 GB RAM, Vista – 2GB RAM
Hard Disk Space: 5.1 GB + 1GB Swap File
Sound Card: DirectX 9.0c compatible sound card
Video Card: 3D Hardware Accelerator Card Required – 100% DirectX 9.0c compatible 128 MB Video Memory
Video Card (ATI): Radeon X800
Video Card (Nvidia): Geforce 7600
Media Required: 4X DVD-ROM drive
Windows XP/Vista compatible mouse and keyboard with latest drivers
Guitar Hero 3 Official PC Guitar Controller

This product does not support Windows 98/ME/2000/NT/XP x64/Vista x64.

MULTIPLAYER REQUIREMENTS:

Internet(TCP/IP) play supported
Internet play requires a broadband connection
RECOMMENDED SYSTEM REQUIREMENTS:

Intel Core 2 Duo 2.4GHZ or AMD Athlon Dual Core 4400+
256 MB 3D Hardware Accelerator Card
Video Card (ATI): Radeon HD 2600
Video Card (Nvidia): Geforce 8800 GT
2 GB RAM
Notice: Some Mobile and Desktop 3D accelerator cards with the chipset listed here may not be compatible with the 3D acceleration features utilized by Guitar Hero 3. Please refer to your hardware manufacturer for 100% DirectX compatibility.

Notice: This game contains technology intended to prevent copying that may conflict with some disk and virtual disk drives.

SUPPORTED DESKTOP CHIPSETS:

ATI RADEON X800
ATI RADEON X1600
ATI RADEON X1800
ATI RADEON X1900
ATI RADEON X1950
ATI RADEON HD 2400
ATI RADEON HD 2600
NVIDIA GEFORCE 7600
NVIDIA GEFORCE 7800
NVIDIA GEFORCE 7900
NVIDIA GEFORCE 8400
NVIDIA GEFORCE 8500
NVIDIA GEFORCE 8800

Notice: The Nvidia Geforce 8400 and 8500 cards have known issues on Vista machines with AMD CPUs.

SUPPORTED MOBILE CHIPSETS:

NVIDIA GEFORCE GO 7600 (XP Only)
NVIDIA GEFORCE GO 7800
NVIDIA GEFORCE GO 7900
NVIDIA GEFORCE GO 8400
NVIDIA GEFORCE GO 8700

I love how it's a generation old midrange ATi card listed and a new top range NVidia card, in the recommended.

I read some posts (by child geeks) that the game runs unacceptably slowly on "minimum" hardware.

child geeks = cheeks

I am denied again!

Hey, that's my old midrange ATI card! Except I've got the x800 GTO. I wouldn't even try to run it on my PC. I'll stick with the PS2.

Speaking of which, I've got hard beat except for Cowboys from Hell. Got up to 98% and lost it! There are two times in the song, one of them towards the end, where you need blue, yellow, red in quick succession. I keep messing that part up. I normally star power the first time, but I can quite make it past the second time so I die at the end.

Oh, I meant the 2600.

On that note Ken what is your preference for Video Cards as I am looking for a new card.

Current system specs:
Gigabyte GA-MA69GM-S2H Mobo
AMD 6400+ AM2
using on board video right now.
2gig PC6400 ram dual channel mode.
500gig WD SATAII
LG DVD writer / lightscribe
Antec Phantom 500 Power supply

All in a small form factor/microATX case
LanBOX Lite by Thermaltake

Anyone else have preferences?

I am torn between Nvidia 8800 series or ATI latest HD.

The system is mostly for gaming(more my 7 yr old son than me) and minor playing around, I can't see myself using it as a HTPC but you never know.

After all I can get this for much cheaper than any stand alone

8800GT. Or the HD 3870. Depending on how much you want to spend or how long you want to wait.

If mostly gaming I would go with a Nvidia 8800GT