Here are similarly configured MacBook Pro and a Dell Inspiron 9400:

Processor: CoreDuo 1.83GHz
RAM: 2GB 667 DDR2
HD: 100GB SATA@7200 rpm
Bluetooth,
Wi-Fi
CD/DVD burner

I used Mac OSX 10.4.4 and WinXP Pro (with the back up CD) (We won't even talk about the features included in the Mac OSX such as iLife)
Went with the UltraSharp display on the Dell.

Differences:
Dell comes with a 17" LCD only. The Mac comes with a 15" LCD only.
Dell comes with a 53 or 80 WHr battery. ($99 more for the 80. Went with the 53 WHr for this)
The MacBook comes with a 60 WHr battery
MacBook comes with ATI x1600 video card, Dell with an NVIDA GeForce Go 7800 (Both with 256 MB)

Prices:
Dell: $3,130
MacBook: $2,899

A $231 difference just on the hardware.